Making change game: check the cashier's answer

Two ways to check a change amount

For a $3.65 purchase paid with $5, subtraction gives $5.00 − $3.65 = $1.35. Counting up gives the same result: add $0.35 to reach $4, then $1 to reach $5. The jumps total $1.35.

The check is $3.65 + $1.35 = $5.00. One way to make that change is one dollar, one quarter and one dime. Another is five quarters and one dime. Both total $1.35; do not mark a valid coin combination wrong merely because it differs from the host's example.

Keep three columns on paper: purchase total, amount paid and change. If the amount paid is lower than the purchase total, there is no change to return; the customer still owes the difference.

Three levels, one checking routine

1. Start with cards 1–4 for whole dollars and quarters. Teams write the change and the addition check.
2. Use cards 5–8 for different cent amounts. Invite a second team to explain a count-up route after the reveal.
3. Use cards 9–12 for exact payment, a convenient extra coin, an incorrect cashier answer and insufficient payment. Read what the question asks before calculating.
4. Rotate customer, cashier and checker roles. Award one paper point for the answer and one for the check. If using play money, accept any combination that totals the correct amount. This is external teaching scoring, separate from Right Price's native scoring.

Twelve original cashier cards

1. 1. Whole-dollar start

   A purchase costs $3.00. The customer pays $5.00. How much change is due?

   Host answer and explanation

   $2.00

   $5 − $3 = $2. Check: $3 + $2 = $5.

2. 2. A ten-dollar payment

   A purchase costs $7.00 and the customer pays $10.00. How much change is due?

   Host answer and explanation

   $3.00

   Count from $7 to $10 in three one-dollar steps. Check: $7 + $3 = $10.

3. 3. Quarter-dollar step

   A purchase costs $4.75 and the customer pays $5.00. How much change is due?

   Host answer and explanation

   $0.25

   Twenty-five cents takes $4.75 to $5.00.

4. 4. Cross a dollar boundary

   A purchase costs $6.50 and the customer pays $10.00. How much change is due?

   Host answer and explanation

   $3.50

   Add $0.50 to reach $7 and $3 to reach $10. Total $3.50.

5. 5. Use a nearby whole dollar

   A purchase costs $3.65 and the customer pays $5.00. How much change is due?

   Host answer and explanation

   $1.35

   Add $0.35 to reach $4, then $1 to reach $5. Check: $3.65 + $1.35 = $5.

6. 6. Cents before dollars

   A purchase costs $8.40 and the customer pays $10.00. How much change is due?

   Host answer and explanation

   $1.60

   Add $0.60 to reach $9, then $1 to reach $10. Total $1.60.

7. 7. A twenty-dollar payment

   A purchase costs $12.85 and the customer pays $20.00. How much change is due?

   Host answer and explanation

   $7.15

   Add $0.15 to reach $13, then $7 to reach $20. Check: $12.85 + $7.15 = $20.

8. 8. One cent matters

   A purchase costs $9.99 and the customer pays $20.00. How much change is due?

   Host answer and explanation

   $10.01

   Add $0.01 to reach $10 and $10 more to reach $20. Keep the one cent in the answer.

9. 9. Exact payment

   The total is $6.25 and the customer pays $6.25. How much change is due?

   Host answer and explanation

   $0.00

   Payment equals the price, so the difference is zero. A zero answer is valid.

10. 10. An extra quarter

    The total is $6.25. The customer gives $10.25. How much change is due?

    Host answer and explanation

    $4.00

    $10.25 − $6.25 = $4.00. The extra quarter changes the amount paid; do not calculate from $10.

11. 11. Audit the cashier

    The total is $13.70 and the payment is $20.00. A cashier offers $5.30 in change. How much additional change is still owed?

    Host answer and explanation

    $1.00

    Correct change is $6.30. The proposed $5.30 is short by $1. The requested answer is the missing amount.

12. 12. Not enough payment

    A purchase costs $8.50. The customer gives $8.00. How much more must the customer pay?

    Host answer and explanation

    $0.50

    $8.50 − $8.00 = $0.50 still owed. This is not negative change and no money should be returned.

Finish with a proof, not only a score

Ask students to invent a purchase that leaves $2.35 change from $10. One valid purchase is $7.65. Require both the subtraction and the check: $10 − $7.65 = $2.35, and $7.65 + $2.35 = $10.

If a student can subtract but struggles to make the amount with money, separate those skills. First accept the correct numeric result, then use drawings or play money to explore combinations. For another currency, replace the denominations and examples deliberately; the numeric amount is the shared-screen answer, while the physical coin representation stays with the teacher.