Teacher Guide

A present is not a trade in the business sense: nothing comes back and the giver expects nothing. Strong answers notice that something does come back (thanks, the relationship) but that it is not something you could price. Both conclusions are fine if argued.

A needs business faces far more competition, because everyone already sells bread. Good answers reach 'more buyers but more sellers'.

A problem that annoys a few people a lot is usually easier to sell to, because those people are already looking for a fix. A problem that mildly annoys everybody has no urgency behind it. Either answer earns credit with reasoning; this one is genuinely contested among adults.

Narrow gains fit and word of mouth; it gives up volume. Both halves needed for full credit.

Two good reasons: they were being polite, and there is a difference between wanting something and wanting it enough to hand over money today. Strong answers name both.

Two shops, same backpack, both sell out: different customers, different convenience, different beliefs about quality. Reject 'the $45 customers were stupid'.

The borrowed table was not free: it cost the ability to keep it, and it cost whatever happens when it is taken back. This is opportunity cost, arrived at without the term.

10 at $5 keeps $41.00; 30 at $2 keeps $33.00. So the higher price wins on this arithmetic, but 30 sales is more customers, more practice and more word of mouth. Both choices defensible; the arithmetic is not.

$8 over six hours is about $1.33 an hour. A student who calls that bad should say what would change their mind: enjoying it, learning, a first attempt, or a better Saturday next time.

Services are hard because the business stops entirely when the person stops. Illness, vacations and school all take the whole business offline.

People pay more for convenience, reliability, brand, ethics, or how it makes them feel. Two named examples with what the extra money buys.

Once rent, power and the owner's own time are added, most small businesses look far less profitable. Students who reach 'the owner is paying themselves last' have understood something real.

Finding an existing solution is good news, not bad. What is still wrong with it is the opening.

The user and the payer are often different: children want, parents pay. Two different messages needed. This is a genuinely advanced idea and worth praising when it lands.

Defending the worst idea teaches that ideas are not good or bad in the abstract, only right or wrong for a customer.

Two deliberately different versions produce better feedback than two similar ones. The reason for the preference matters more than the preference.

Deciding whether the one dissenter matters depends on whether they are your customer. A non-customer's dislike is not a signal. Students who ask 'were they the sort of person I am building for?' understand it.

The trade-off is real: better and slower against faster and rougher. Force the arithmetic before the opinion.

With one in ten wasted, ten items cost $8.00 but only nine are sellable, so the real cost is about 89 cents each. Students who find this have met spoilage honestly.

$4.99 works on perception but is a nuisance in coins at a school market. Students who mention the line have thought about operations.

Raising the price by 50 cents and selling a quarter fewer (15 instead of 20) wins only when profit on one sale is under $1.50, because 15 x (profit + 50 cents) beats 20 x profit only then. With the warm-up numbers ($2.30 on one), 20 sales make $46.00 and 15 sales at the higher price make $42.00, so the higher price loses. Require the arithmetic both ways with the student's own numbers.

Teaching costs 30 of your minutes and buys 90 minutes of the friend's work (their 2 hours minus the 30 spent learning), or 120 if the teaching comes first. If the friend works as fast as you, accepting always wins: 90 minutes of their making against 30 of yours. It loses only if they are about three times slower than you or worse, or if one item takes longer than their whole shift, so they finish nothing.

A label size dividing evenly into 12 by 8 (2x2, 3x2, 4x2, 6x4) wastes nothing. Checking the name still fits is the part they forget.

Selling only half is the realistic case. If half still clears zero, the plan is sound. If not, the break-even number is the one that matters and it should go on the plan.

A trick line works once and then costs trust. Good answers name the second encounter.

Cutting a 22 by 28 sheet with minimal waste is a real optimization problem. Accept any layout with the arithmetic shown.

Handling an interruption without restarting is the advanced skill. Answer the question, then return to the sentence you were on.

'Too expensive' has two different meanings and two different answers. Students who write only a discount have missed it.

If you spend the whole fund and sell half of what you made, whether you can repay depends entirely on your margin. At a price of twice cost, selling half gets you back exactly to the fund and no further. Students who reach that are doing break-even reasoning without the term.

Market size, and the reason play money earns its place. Tell students the shopper allowance and the expected number of shoppers. Allowance times shoppers is all the money there is; divided by the number of stalls is an even share. A student planning to take three times an even share has just learned something about their forecast that no amount of encouragement would have taught them. With real money none of this is knowable.

Prediction against reality is the single most useful reflection of the year. Over or under, the size of the gap is the finding.

Average sale and the effect of three more customers shows how sensitive a small stall is to a handful of people.

Doubling profit can need more sales than the day's foot traffic allowed. If it does, that constraint is a real finding, not a failure.

Arguing the opposite case tests whether the conclusion was reasoned or assumed.

Risk appetite depends on what else the money is for and how confident they are that it will sell. Two named pieces of information.

The three most useful things to tell next year's class are almost never on the one-page plan, which is the closing observation of the year: the plan holds the numbers, the experience holds the rest.