THE PRACTICE COLLECTION / VOL. 100
Composure, software, sales, and more. Turn what you know into something you can demonstrate. Pick one useful exercise from 100 drills across 10 connected disciplines.
01 / CHOOSE YOUR DIRECTION
Follow a route in order, or choose the one exercise you need. You can spread the five drills across several days.
5 STEPS / trust
Composure → updates → commitments → quality → reflection
This route 0 / 5You have confirmed all five drills in this route. Choose another route or revisit an exercise.
Times are estimates. Stopping partway through is not a failure.
5 STEPS / build
Problem → design → implementation → tests → operations
This route 0 / 5You have confirmed all five drills in this route. Choose another route or revisit an exercise.
Times are estimates. Stopping partway through is not a failure.
5 STEPS / launch
Discovery → proposal → message → measurement → economics
This route 0 / 5You have confirmed all five drills in this route. Choose another route or revisit an exercise.
Times are estimates. Stopping partway through is not a failure.
5 STEPS / invent
Observation → assumptions → alternatives → prototype → test
This route 0 / 5You have confirmed all five drills in this route. Choose another route or revisit an exercise.
Times are estimates. Stopping partway through is not a failure.
5 STEPS / partner
Listen → expectations → roles → alignment → reflection
This route 0 / 5You have confirmed all five drills in this route. Choose another route or revisit an exercise.
Times are estimates. Stopping partway through is not a failure.
5 STEPS / balance
Reset → build → communicate → collaborate → measure
This route 0 / 5You have confirmed all five drills in this route. Choose another route or revisit an exercise.
Times are estimates. Stopping partway through is not a failure.
02 / YOUR PRACTICE LIBRARY
Open a brief and work through it using the fictional scenario. Try your own answer before opening the example, then check the three success criteria.
No drills match these filters. Try allowing more time or choosing a different level.
The brief
In a fictional shared task, someone has not replied to your request for a review. The agreed response time has not yet passed.
One sentence each for the fact, possible interpretations, and next check.
Fact: There is no reply yet. Possibility: They may not have reviewed it. After the agreed time, ask, “When do you expect to be able to review this?”
Treating response speed as a complete measure of how someone values you.
The brief
You were making a fictional information card when another task interrupted you. Now you cannot remember where to restart.
One completed action and a clear starting point for the next one.
The heading is done. Add “a pen” to the supplies list. Next time, begin with the first line of the venue directions.
Trying to rebuild the entire project before taking a single step.
The brief
A fictional notice receives this feedback: “Too much text. Please shorten it.” You feel discouraged.
One clarification question and one shorter notice.
Ask, “Should I keep the arrival time and supplies?” Revised notice: “Arrive ten minutes early and bring a pen.”
Turning one request for a revision into “I cannot do anything well.”
The brief
You practiced a fictional explanation. You stumbled over a phrase, but you did ask a question to check understanding.
Three lines: what you did, what comes next, and where you stop.
Done: I checked understanding. Next time: shorten the opening to one sentence. That is enough for today.
Cancelling every useful observation by immediately adding “but.”
The brief
For a fictional event, you are thinking about tomorrow’s notice, next week’s supplies list, and a venue-time check due today.
An ordered list of three tasks and a priority-check question.
Check the venue time, then draft tomorrow’s notice, then prepare next week’s list. “Does this order fit our priorities?”
Starting whichever task comes to mind and leaving all three unfinished.
The brief
A large table is no longer available for a fictional display. A smaller table is available.
A fixed constraint, two options, and one question.
Fixed: The large table is unavailable. Options: show fewer items or rotate the display. Ask the organizer how much aisle space is required.
Treating “the original plan changed” as “nothing can be done.”
The brief
In a fictional practice map, you marked entrance A as the meeting point, but entrance B is correct. The training map has not actually been distributed.
An unsent correction draft and one verification item.
“The entrance shown on the map is incorrect. The correct meeting point is entrance B. I will check the location and arrow on the revised map. I am sorry for the error.”
Spending so long blaming yourself that the correction and impact check are delayed.
The brief
Your explanation ran long in a fictional meeting. You have prepared a shorter opening for next time, but keep replaying the same moment.
One lesson, the status of remaining action, and an ending sentence.
Lesson: Start with the conclusion. The shorter opening is ready. No further action is needed now. I am taking a break.
Making “I no longer feel bothered” a requirement for ending reflection.
The brief
A fictional proposal receives only “Make it better” as feedback. You do not know what is missing or where to start.
Two possible answers, each with a revision and review plan.
“Should I focus first on readability or supporting evidence?” For readability, shorten the opening; for evidence, add one verified finding.
Revising every section extensively before understanding what needs improvement.
The brief
In a fictional learning plan, you intended to practice explanations for thirty minutes every time. The time available varies from day to day.
Two practice options and a three-day plan that includes rest.
Five minutes: explain the idea in one sentence. Twenty minutes: rehearse answers to two questions. Skip a crowded day and adjust the plan at the next review.
Treating every skipped day as a debt that must be repaid.
The brief
You are preparing a fictional book-club notice. The text is complete, but the room number is still awaiting confirmation.
A three-sentence update you can say aloud.
The notice text is complete. The room number is unconfirmed, so the final distribution copy is not ready. Should we ask the venue coordinator to confirm the number?
Giving a long history without making the current status and needed check clear.
The brief
You are asked to make a fictional guide “clear for first-time users.” Its length and setting have not been agreed.
Three questions and a proposed definition of done.
“Who will read this, and where? What should they be able to do afterward?” Proposed criterion: a first-time visitor can identify the reception area from the guide.
Defining clarity only through your own preferences.
The brief
In a fictional meeting, someone says, “Appearance matters, but making it easy to use comes first.”
An initial summary and a corrected version.
“Have I understood correctly that ease of use comes first, with appearance next?” After clarification: “So the first priority is reducing confusion for first-time users.”
Using a summary to steer the other person into agreeing with your own proposal.
The brief
A fictional display card is due this afternoon, but its illustration is awaiting review. You can provide the text at the agreed time.
An unsent draft that flags the delay and offers choices.
The illustration is awaiting review, so the final version has no confirmed completion time. I can provide the text as planned. Would you like to review that first?
Waiting for complete certainty until the other person has no time to adjust.
The brief
In a fictional task, you are asked to make a new diagram as well as revise a notice. Completing both within the agreed time looks unlikely.
A response containing two adjustment options.
I can finish the notice revision within the agreed time. If the diagram comes first, the notice will need to move later. Which should take priority?
Silently accepting a workload you already expect to be unmanageable.
The brief
During a fictional instruction rehearsal, a speaker skips a step and the listener hesitates over the next action.
An initial feedback statement and an adjusted request.
Step two was not explained, and the listener hesitated over which button to press. Could you show the numbered steps in order next time? Was there a time constraint?
Turning a specific improvement into a judgment of someone’s personality or overall ability.
The brief
For a fictional display, one person favors a single large sign while another favors several smaller signs.
A shared purpose, comparison criteria, and a small comparison plan.
The goal is helping visitors find reception. Could we use a model to compare hesitation and missed signs, then discuss what we observe?
Describing the other person’s option unfairly before comparing it with your own.
The brief
In a fictional shared project, someone says, “The instructions feel rushed.” You do not yet know which part they mean.
Four sentences: a question, an understanding check, a repetition request, and a next step.
“Which step needs more explanation?” “Do you mean step two?” “Could you say that again more slowly?” “I will add an example to step two.”
Pretending to understand and starting a revision based on unconfirmed information.
The brief
In a fictional event meeting, the group agrees to try a paper guide first. Ownership, a review date, and whether to include a diagram remain undecided.
A meeting summary with clear decisions and open items.
Agreed: Try a paper guide first. Open: Whether to include a diagram. Proposal: The drafting role prepares one version before our next meeting. Does that match your understanding?
Recording an idea mentioned in discussion as an agreed decision.
The brief
In a fictional shared task, you said you would review something that afternoon. The agreed time has passed without the review.
A draft containing an apology, a repair proposal, a new-agreement request, and a progress check.
I have not completed the review I promised this afternoon, and I am sorry. How does this affect your next step? I will check the remaining scope now so we can agree on a realistic review time.
Promising an even tighter deadline on impulse to try to restore trust.
The brief
This fictional consultation was requested by the other person. You plan to discuss information materials, but do not yet know what they want from today’s conversation.
Two opening sentences and a response to each possible answer.
“Would now be a good time for ten minutes? What would be useful to work through today?” If time is unavailable: “Understood. Let us stop here for today.”
Assuming a requested consultation gives you permission to complete your entire prepared presentation.
The brief
In a fictional consultation, someone says creating event notices is difficult. You do not yet know which part takes the effort.
An opening question and two answer-specific follow-up questions.
“How did you put together your most recent notice?” For materials: “Where did you look?” For review: “At which stage did progress stop?”
Choosing a product or feature based only on the word difficult.
The brief
A fictional notice coordinator says revisions can delay distribution. You do not know how often this happens or how long the delays last.
Three questions and a clear separation of knowns and unknowns.
“How often does this happen? What changes in the work afterward? Where does this sit among the issues you want to address?” Leave frequency marked as unknown.
Adding an imagined loss or urgency to make the problem sound larger.
The brief
A fictional customer wants creating notices to be more convenient. They have not asked for a particular feature.
An improvement criterion and two questions to check it.
“Would it help if reviewers could see what changed from the notice itself? What works about the current approach that you would want to keep?”
Treating the number or novelty of features as the definition of convenience.
The brief
You are practicing a proposal for a fictional notice service. The exercise establishes two conditions: paper notices are supported, with one revision. Digital distribution and time savings are unverified.
A three-column outline and a short proposal with evidence and limits.
We can provide paper notices with one revision. Digital distribution and time savings remain unverified. Would comparing ease of review with fictional drafts be a useful first trial?
Treating the presence of a feature as proof that it will produce a particular outcome.
The brief
Someone calls your fictional proposal expensive. You do not know whether the total is unaffordable or the included work is unclear.
One clarifying question and a response to each answer.
“What concerns you most about the cost?” For budget: “We could explore a smaller scope.” For clarity: “Let us separate the included work from anything charged additionally.”
Discounting before understanding the concern and leaving the real issue unresolved.
The brief
In a fictional consultation, the other person clearly says, “Our current approach is enough. We do not need this.”
A response to a clear no and one to a customer-initiated future conversation.
“Understood. We will leave it here. Thank you for your time.” If they say they will contact you later: “Understood.”
Treating a refusal as a cue to restart the persuasion from a different angle.
The brief
Changes are hard to spot in a fictional event notice. Options include keeping the current process, adding a review checklist, or trying a small notice service.
A one-page proposal draft comparing three options.
Keeping the process requires no setup change. A checklist needs preparation. A service trial requires cost and revision-scope checks. Compare how easily changes can be found in model drafts.
Explaining only your preferred option and omitting the strengths of alternatives.
The brief
A fictional customer is interested in improving notices but cannot decide on adoption alone. Required approvals and user checks are still unclear.
A role-based decision outline and one point to clarify next.
“If you explore this, in what order would user review and cost approval be needed?” Map a fictional sequence: review by intended users, followed by budget approval.
Bypassing the conversation partner to contact or pitch another decision-maker.
The brief
In a fictional notice-service negotiation, someone asks for more revisions and an earlier deadline at the same price. For this exercise, you have no authority to change the terms.
Two options and a response clearly marking them as unapproved.
“Which matters more: the revision allowance or the deadline? Changes need approval. We could explore a smaller scope for earlier delivery, or discuss revisions while keeping the original date.”
Agreeing to unverified delivery conditions to secure the sale quickly.
The brief
A fictional library guide requires comparing three calendars to find an open branch.
An action list and a problem statement with supporting evidence.
Problem: the same date must be found on three calendars. Hypothesis: selecting it once will make comparison easier.
Calling the interface confusing without identifying an action to change.
The brief
You are considering a fictional park drinking-fountain guide without location tracking.
Five assumptions and one priority check.
Untested: outage information can be maintained. Check: add one fictional outage and rehearse updating every affected display.
Assuming information will stay accurate because the interface is easy to build.
The brief
Items are difficult to find in a practice guide containing invented sorting rules.
Three sketches and a reasoned selection.
Try a list for ten items. Search may be faster, but it needs a strategy for alternative item names.
Developing the favorite option thoroughly while leaving the alternatives too vague to compare.
The brief
Design a fictional exhibition guide with no connection, one screen, and no registration.
A single-screen design and an update rule.
Bundle exhibit names, locations, and descriptions; label them “Practice data, version 2; no automatic updates.” Replace the file to update.
Moving essential work to another screen or service to sidestep the constraints.
The brief
Closure notices get lost among regular hours in a fictional library guide.
An explanation of the borrowed mechanism and three state sketches.
Borrow the idea of showing status first from traffic signals. Place “Open,” “Closed,” or “Unverified” beside each library name.
Copying colors and shapes without improving how information is communicated.
The brief
You expect category buttons to reduce confusion in a fictional exhibit search.
A check plan with adoption, revision, and inconclusive conditions.
Revise if category names create more hesitation. Remain undecided if all three tasks are too easy to reveal a difference.
Changing the definition of success after seeing the result.
The brief
A fictional equipment catalog might benefit from an availability filter. No personal loan records are involved.
Six prototype cards and a list of discovered gaps.
Finding an available tripod required both status and equipment type. Test a type filter next.
Spending the session polishing the cards instead of testing the interaction.
The brief
Compare a paper list, a static page, and date search for an invented opening-days guide.
A three-by-three comparison and a conditional recommendation.
Try a static page when updates are monthly and everything fits on one screen. Reconsider search when date comparisons become frequent.
Claiming no competing product exists without researching actual alternatives.
The brief
In an isolated practice environment, check whether bundled exhibit data can be searched without a connection.
The minimal function, three check results, and an untested-scope note.
Verified: the bundled array is searchable. Unverified: initial distribution, storage limits, and data updates.
Treating a successful technical experiment as evidence that the whole product will work.
The brief
An invented equipment-search trial works by category, but its availability labels are misunderstood.
A one-page decision with evidence and a future decision rule.
Change the labels and retry two fictional tasks. If confusion remains, defer availability search.
Using the amount already built as the main reason to continue.
The brief
A fictional exhibition guide has only the vague objective “make things convenient.”
One usage scenario and two feature decisions.
At the entrance, a visitor finds an interesting exhibit’s location. Needed: exhibit list. Unneeded for now: a profile.
Adding elaborate personal attributes instead of clarifying the task.
The brief
Specify date selection for a fictional library search.
Three acceptance criteria with inputs, actions, and outcomes.
Select an unrecorded date → display “Information is unavailable for this date,” not “All branches closed.”
Specifying only success and treating missing information as a closure.
The brief
A fictional facility search has a design only for successful results.
A five-state transition diagram.
Loading → network failure → error display → retry → loading. Preserve the query after failure.
Adding an error message without a route out of the error state.
The brief
An invented library guide has six ideas: date search, maps, accounts, notifications, languages, and favorites.
Six classified ideas and one release-scope sentence.
Now: date search and bilingual guidance. No accounts, alerts, or favorites yet. Investigate the need for a map later.
Cutting essential error states as though they were optional extra features.
The brief
A fictional equipment list contains chairs, tables, tripods, lights, cables, and microphones.
A category diagram and six navigation checks.
Use “Furniture” and “Photo and audio.” Put cables in the latter, with an all-items view as another route.
Naming categories solely around the builder’s administrative needs.
The brief
A fictional exhibit list includes category selection and links to details.
A wireframe with navigation order and three state descriptions.
1 “Choose category” → 2 “Search” → 3 “Exhibit details.” Show selection with text and a shape change.
Treating a wireframe as proof of accessibility and skipping interaction checks after implementation.
The brief
A fictional facility guide labels invalid input, no matches, and network failure simply “Error.”
A bilingual table of six messages covering three states.
「施設を読み込めませんでした。もう一度試してください。」 / “Could not load facilities. Try again.”
Suggesting different filters when the actual problem is a failed connection.
The brief
Compare a list and cards for finding exhibits in an invented guide.
Two tasks, a trial script, and a blank observation table.
Task: “Find one outdoor exhibit.” Record whether it was completed and which label caused hesitation.
Calling a control convenient in the instructions before evaluating whether people can use it.
The brief
In invented trials, the old version completed 8 of 10 tasks; the new version completed 12 of 20.
A calculation table and a qualified interpretation.
More tasks were completed, but this trial’s completion rate fell. Repeat equivalent tasks before interpreting the difference.
Selecting only the number that makes the new version look better.
The brief
A fictional opening-days guide has working search and two languages, but missing dates are incorrectly shown as closed.
A release decision and explicit reconsideration conditions.
Delay. Correct missing dates to “Unrecorded,” then verify open, closed, and missing states in both languages before reconsidering.
Giving the number of completed features more weight than an unresolved misleading result.
The brief
Filter three invented exhibits by category in an isolated local environment.
A filter function and outputs for three cases.
const select = (items, category) => items.filter(item => item.category === category);
Deleting elements from the source list while filtering.
The brief
A local fictional library dataset treats an unrecorded opening status as a closure.
State definitions, a display function, and four results.
open → Open; closed → Closed; unknown → Unverified; other → input validation error.
Using an empty string, null, or false to represent several different meanings.
The brief
Use a disposable local PostgreSQL database for fictional facilities and opening dates.
Two table definitions and three insertion outcomes.
Opening dates: facility_id NOT NULL, day NOT NULL, a foreign key to facilities, and UNIQUE(facility_id, day).
Allowing nulls in the uniqueness columns without considering how they affect duplicate handling.
The brief
Search fictional facility names containing an apostrophe in an isolated practice database.
A parameterized search and three results.
PostgreSQL structure: SELECT id FROM facilities WHERE name = $1, with the value array passed separately.
Treating manual quote replacement as a substitute for parameterization.
The brief
Practice building the interface and server separately for a local fictional facility API.
A one-page API contract and three response examples.
Results: {"items":[{"id":"F1","label":"Demo Hall"}]}; empty: {"items":[]}; invalid: {"error":"invalid_filter"}.Returning null for both an empty result and a connection failure.
The brief
Write a local paginator for fictional exhibits, with three items per page and page numbers starting at one.
A paginator and a record of its test detecting the defect.
items.slice((page - 1) * 3, page * 3). Input [A,B,C,D] with page=2 should return [D].
Calculating expected values with the same logic as the implementation and repeating its mistake.
The brief
Update an invented exhibit’s state and version together in disposable local PostgreSQL.
Results for one canceled update and one successful update.
Initially: draft/1. After cancellation: draft/1. After committing both changes: published/2.
Committing the first update separately while assuming the operations still form one transaction.
The brief
Prepare 10,000 invented rows with sequential IDs and categories in disposable local PostgreSQL.
Before-and-after plans, row counts, and a decision.
Record scan type, returned rows, measured duration, and index presence. Repeat small differences before drawing conclusions.
Forgetting that EXPLAIN ANALYZE executes the statement and trying it on updates or production.
The brief
A local fictional exhibit-search prototype combines loading, filtering, and HTML rendering in one function.
Before-and-after code and a dependency diagram.
loadDemoData → selectExhibits → renderList. A category-rule change can be checked in selectExhibits independently.
Adding many services or abstract classes to solve a small separation problem.
The brief
Modify a fictional list-filter function in a disposable local Git repository without publishing it remotely.
A focused diff, tests, and a review note.
Purpose: an empty query returns all items. Cases: empty, matching, and unmatched queries. CI check command: node --test.
Reporting that checks passed without explaining what behavior the tests protect.
The brief
Five fictional searches produce success, success, failure, success, and success.
A metric definition and one calculation.
Metric: searches whose outcome is correctly displayed divided by searches attempted. This sample is 4/5.
Treating a server response as proof that the user completed the task.
The brief
Add diagnostic records to a local fictional search app.
An allowed-field definition and two example records.
{"event":"demo_search","status":"error","duration_ms":80}Recording entire requests or responses simply because they might be useful later.
The brief
Use a stub to simulate fictional data-loading failures in a local prototype with no network calls.
A recoverable interface and a check note.
Loading → “Could not load” with Retry → fictional facility list. No external requests are made.
Showing an error while leaving the loading state active.
The brief
A local fictional exhibition page is blank because its practice data failed to load.
A practice runbook of no more than five steps.
Confirm isolation → check file existence → validate format → restore known-good practice data → verify three displayed entries.
Writing a loop of repeated restarts without investigating the cause.
The brief
In an isolated practice folder, prepare a correct fictional guide as v1 and a v2 with its heading missing.
Rollback instructions and three post-recovery checks.
Stop: main heading missing. Return to v1. Verify: heading present, three fictional branches present, version label v1.
Assuming the previous version can be recreated later instead of preserving it.
The brief
Add summary to local fictional exhibit JSON that previously contained only id and title.
A compatible reader and three check results.
Missing summary → “Summary not available.” Numeric summary → validation error. Preserve the original practice JSON.
Testing only new data and overlooking the period when old records still exist.
The brief
A fictional exercise sets a 99% success target for 1,000 operations in a fixed window. Twelve operations failed.
The calculations and one proposed next task.
The budget is exceeded. Fix the invented loading failure first and check recovery with the same metric definition.
Removing failed operations from the denominator to hide a missed objective.
The brief
Compare local functions searching 1,000 fictional exhibits in isolation. Send no load to external systems.
Ten measurements and a qualified conclusion.
Run 100 calls per measurement. If timing ranges overlap, record “No clear difference in this measurement.”
Selecting one unusually fast run and forgetting to check output correctness.
The brief
Practice read and update authorization for fictional exhibits in a local server-like function, without real accounts.
A permission matrix, authorization function, and six results plus a spoofed-input check.
A reader context with role:editor in the request body still cannot update. This exercise does not implement authentication.
Assuming that hiding an update button protects the update operation.
The brief
Rehearse releasing v2 of a fictional exhibition guide using paper records and an isolated environment, without a real deployment.
A rehearsal record and revised response instructions.
v2 list missing → stop → restore v1 → verify three entries in Japanese and English. Add version identification to the instructions.
Reading the procedure without making the decisions required by an actual scenario.
The brief
A fictional desk organizer kit is described only as “for people who want to tidy up.”
One statement covering the person, situation, problem, and buying criterion.
Assumption: Someone keeps stationery in a box on a small desk but struggles to reach it. They want measurements to check whether an organizer fits the available space.
Writing “for everyone,” or presenting an imagined problem as an observed fact.
The brief
The fictional organizer kit has a prototype but no customer track record.
A note containing the scope, product statement, and evidence.
Prototype organizer kit with parts and instructions; tools are separate. A dimension sheet and assembly photos let buyers check the space and work required.
Using untested benefits or fictional customer reviews as evidence.
The brief
Dimensions and assembly instructions are available for a fictional kit. This is a writing exercise with no ad publishing.
Two headlines, each with evidence and a next action.
A: “Find an organizer that fits your desk”—view dimensions. B: “See how the organizer goes together before you choose”—view assembly photos.
Changing only the wording without knowing what distinction you want to compare.
The brief
A fictional ad says “Check which size fits your desk.” You are planning its destination on paper.
A four-part page outline and a consistency check.
Dimensions and placement photos → parts and materials → price and delivery terms → view full specifications. Use the same kit throughout.
Sending an ad about dimensions to an unrelated general page.
The brief
Fictional data for one period: 10,000 impressions, 200 eligible clicks, 8 purchases, and ¥12,000 in ad spend.
Three calculations and a note about an unresolved question.
200 ÷ 10,000 = 2%; 8 ÷ 200 = 4%; ¥12,000 ÷ 8 = ¥1,500. Without product costs, profitability remains unknown.
Mixing denominators or declaring success from click-through rate alone.
The brief
A fictional report contains 30 inquiries, 12 that fit the service, 5 quotations, and 2 orders.
Definitions for four stages and a counting rule.
Main outcome: 2 orders. A fitting inquiry matches the service scope and requested timing. Follow-up messages about the same request do not count as new inquiries.
Combining document views and orders into a single outcome to inflate the count.
The brief
You are planning a fictional pre-launch comparison of headlines emphasizing dimensions or assembly.
A plan covering the hypothesis, change, shared conditions, and evaluation.
Hypothesis: People with limited space respond to dimensions. Plan a concurrent comparison with the same audience, product, and page. With very few purchases, leave the result unresolved.
Changing the headline, price, and audience together and attributing the result only to the headline.
The brief
A fictional practice plan has a ¥6,000 total cost limit and ¥5,400 recorded so far. You will not operate a real campaign.
The remaining amount and a stop, verify, and resume procedure.
¥600 remains. The campaign role stops before the limit, allowing for reporting delay, and verifies delivery has stopped. A broken destination triggers an immediate stop. Resume only after review and separate approval.
Assuming a notification received after the limit is reached will prevent overspending.
The brief
You have 120 fictional preparation minutes: a FAQ article takes 60, product-listing copy takes 30, and a referral information sheet takes 30.
A plan covering three content roles, next steps, preparation time, and observations.
The FAQ answers “Will it fit?”, the listing explains the contents, and the referral sheet identifies who it suits. Total: 120 minutes. Each points to specifications; views and purchases are counted separately.
Treating preparation and maintenance as free. Do not publish or send materials outside this exercise.
The brief
Fictional data for one period: A has 10,000 impressions, 1,000 clicks, 32 completed deliveries, and ¥40,000 ad spend. B has 10,000 impressions, 600 clicks, 29 completed deliveries, and ¥24,000 ad spend. Both sell at ¥5,000 with ¥2,000 variable cost per delivery.
Click-through rates, contribution figures, and the next checks.
A: 32 × ¥3,000 − ¥40,000 = ¥56,000. B: 29 × ¥3,000 − ¥24,000 = ¥63,000. B leaves more this time. Check fixed costs, fulfillment capacity, and comparable conditions before deciding what comes next.
Choosing A from its higher click-through rate alone, or assuming this period’s results will repeat.
The brief
Two people are preparing a fictional display. One prioritizes explaining it to visitors; the other prioritizes the finish of the display itself.
Three lines: shared purpose, difference, and a first agreement proposal.
Shared purpose: help first-time visitors understand the display. Difference: rehearsal versus finishing work. Could we first make one exhibit ready to explain and review it together?
Saying “We have the same goal” without exploring different expectations.
The brief
You are jointly making a fictional information card. Ownership of the text, illustration, and final review is unclear.
An ownership and handoff outline for three tasks.
The writer gives a heading and text to the illustrator before the next meeting. The illustrator passes a layout to the reviewer. The reviewer returns specific changes to both.
Making everyone responsible without deciding who takes the first action.
The brief
Several layout ideas have been proposed for a fictional event. The organizer role has final approval.
A role-based decision process and examples of proposed versus approved status.
The drafting role proposes a layout, the usability role checks the aisles, and the organizer approves. “Option A is under review. We will share the final layout after approval.”
Treating the loudest opinion as an approved decision.
The brief
In a fictional collaboration, you said, “I will prepare something later.” The other person does not know its scope or timing.
A commitment sentence with clear scope and timing.
I can prepare one text-only draft before our next meeting. It will not include the illustration yet. Would that be a useful stage for your review?
Promising to handle everything without defining what that means.
The brief
An illustration for a fictional display is late. You can still review the text and prepare the backing board.
A status-check question and two work sequences.
Could you share the current outlook and anything making progress difficult? If the illustration arrives soon, we can check the layout; otherwise, we can review the text and prepare the board first.
Letting one delayed dependency stop every other useful task.
The brief
A fictional project originally covered one display notice. A takeaway card is now requested as well, with the same deadline.
A discussion draft showing the change and two adjustment options.
The takeaway card is additional to the agreed notice. We could finish the notice first and prepare the card later, or reduce the content of both. Could we agree on which takes priority?
Accepting an addition as small without explaining its effect on the original commitment.
The brief
In a fictional joint presentation, one person wants a shorter explanation while another wants detailed cautions.
Two underlying needs and one option to try.
Imagine that one role is concerned about listener fatigue and the other about misuse. Put the essential caution first, with detail in a supplement, and rehearse the explanation together.
Making the other person’s concession the only acceptable resolution.
The brief
Two people have finished a fictional explanation rehearsal. They want to exchange feedback, but tend to suggest too many changes at once.
Short feedback from both roles and the next change to try.
“Showing the numbers made the order clear. There was hesitation when the tool appeared. Could you try pointing to the tool next time?” Reply: “I will try that and leave the wording unchanged for now.”
Listing so many improvements that the other person cannot choose a next action.
The brief
In a fictional joint project, revisions repeatedly arrive just before completion. You want to examine the review process without assuming someone is not trying hard enough.
A workflow, two hypotheses, and a one-round improvement trial.
Possible causes: unclear completion criteria or no early review. Next time, review the headings once before drafting. Compare late revision work and added review time, then decide whether to continue.
Using reflection to assign blame without changing the working process.
The brief
One person’s assignment on a fictional display is ending. The notice is complete, an illustration awaits review, and the layout remains undecided.
A handoff organized by three states and a proposed end to the assignment.
Complete: notice A. Pending: illustration B goes to the reviewer. Undecided: the organizer must decide layout C. Propose gathering questions until the next handoff review, after which the new owner handles changes.
Saying “Contact me anytime” without clarifying unresolved decisions or the end of ownership.
The brief
In a fictional card-making exercise, each sale brings in ¥1,200 and incurs ¥700 in variable costs. No other costs are included here.
A per-unit calculation and its percentage of revenue.
1,200 − 700 = ¥500. 500 ÷ 1,200 × 100 ≈ 41.7%. This contribution is available before covering fixed costs.
Treating the entire ¥1,200 selling price as profit.
The brief
A fictional guide-card exercise sells eight units at ¥1,500 each. Variable cost is ¥600 per unit and total fixed cost is ¥2,000. Exercise profit deducts only these stated costs.
A table of revenue, variable costs, fixed costs, and profit.
¥12,000 revenue − ¥4,800 variable costs − ¥2,000 fixed costs = ¥5,200 profit.
Deducting only per-unit costs and forgetting the fixed total.
The brief
A fictional booklet sells for ¥1,000, costs ¥400 per sold copy to produce, and has ¥3,000 in fixed costs. Only sold copies are produced; there are no other costs.
The break-even quantity and three surrounding profit calculations.
3,000 ÷ (1,000 − 400) = 5 copies. Profit = 600 × copies − 3,000.
Dividing fixed costs by the selling price while ignoring per-copy costs.
The brief
A fictional practice account starts with ¥5,000. Materials cost ¥3,000 now, and an ¥8,000 delivery payment arrives the next day. There are no other cash movements.
Three balances and a payment-feasibility check.
After materials, ¥2,000 is ¥500 short of the extra payment. After receipt, paying ¥2,500 from ¥10,000 leaves ¥7,500.
Counting an invoiced amount as cash before receiving it.
The brief
A fictional production exercise has 420 minutes available, a one-time 60-minute setup, and 120 minutes of production and checking per item. Items are handled sequentially.
Completed-item capacity and the time shortfall for four items.
(420 − 60) ÷ 120 = 3 items. Four require 60 + 120 × 4 = 540 minutes, a 120-minute shortfall.
Promising a quantity based on production time alone while omitting setup or checking.
The brief
Two fictional options assume ten sales at ¥2,000 each or eight sales at ¥2,200 each. Both have ¥800 variable cost per sale and ¥4,000 fixed costs, with no other costs.
A two-option calculation and an assumption-qualified comparison.
Current: 20,000 − 8,000 − 4,000 = ¥8,000. Changed: 17,600 − 6,400 − 4,000 = ¥7,200. These quantity assumptions produce ¥800 less.
Using a higher unit price alone as evidence of higher profit.
The brief
A fictional model-making exercise produces ten units, discards two defective ones, and sells eight. Price is ¥1,500, materials cost ¥500 per unit produced, and fixed costs are ¥1,000. There are no other costs.
Calculations with and without the two discarded units.
With defects: 12,000 − 5,000 − 1,000 = ¥6,000. Without defects: 15,000 − 5,000 − 1,000 = ¥9,000.
Counting materials only for the eight sold units and erasing the cost of discarded units.
The brief
A fictional baseline has a ¥1,000 price, ten sales, ¥400 variable cost per sale, and ¥3,000 fixed costs. Compare eight sales, a ¥500 variable cost, and both changes together. Everything else stays the same.
Four profits and their differences from baseline.
Both changes: (1,000 − 500) × 8 − 3,000 = ¥1,000, which is ¥2,000 below baseline.
Forgetting that total variable costs also change when sales quantity changes.
The brief
This fictional allocation exercise has ¥5,000 and requires keeping ¥3,000. Tool A costs ¥2,000 and is assumed to save six minutes per task. Template B costs ¥1,000 and saves three. The goal is at least 40 minutes across ten tasks. Combined savings add together. Make no actual purchase.
Three-option comparison, conditional selection, and a validation plan.
Choose A within this exercise: ¥3,000 remains and assumed savings are 60 minutes. B misses the time target; both miss the cash floor. Test one invented task under comparable conditions.
Looking only at potential savings and spending cash that the plan requires retaining.
The brief
In a fictional order exercise, A sells for ¥1,800, costs ¥600, takes 30 minutes, and has a four-unit limit. B sells for ¥2,800, costs ¥1,000, takes 60 minutes, and has a two-unit limit. Available time is 180 minutes; fixed costs are ¥1,200. Times include checking, there are no other costs, and quantities are nonnegative integers.
A fifteen-combination comparison and the best feasible option.
A4 plus B1: ¥10,000 revenue − ¥3,400 variable costs − ¥1,200 fixed costs = ¥5,400. Time: 4 × 30 + 60 = 180 minutes. This result applies to the stated conditions.
Prioritizing the higher-priced B without considering time per unit and quantity limits.
SMALL STEPS, REAL PRACTICE
Checks disappear when you reload the page. A small practice day still counts as practice.
AMBITION WITH COMPOSURE
Great software and useful businesses grow through small experiments and dependable relationships. Try one drill today, then choose one thing to apply tomorrow.
Choose today’s route ↑These original exercises use fictional scenarios. Related official resources are collected in the Growth Practice Room.