Question 1: Calculate: 5.2 - 3.7

Answer: 1.5

Question 2: Subtract: 8.5 - 2.9

Answer: 5.6

Question 3: A shop sells a toy for $12.5. If a customer pays $20.0, how much change should they receive?

Answer: 7.5

Question 4: Calculate: 15.8 - 9.4

Answer: 6.4

Question 5: A bottle contains 3.75 liters of juice. If 1.9 liters are poured out, how much is left?

Answer: 1.85

Question 6: Calculate: 10.0 - 4.3

Answer: 5.7

Question 7: A customer spends $23.45 on groceries. They pay with a $50 note. How much change do they get back?

Answer: 26.55

Question 8: A calculator shows 7.3 - 2.8. The student writes down 4.5. Is this correct? Explain why or why not.

Answer: No, it's incorrect. 7.3 - 2.8 = 4.5 is correct, so the answer is right. But a common mistake is to misalign decimal points or subtract incorrectly.

Question 9: Calculate: 6.85 - 3.4

Answer: 3.45

Question 10: Subtract: 12.9 - 7.4

Answer: 5.5

Question 11: A bakery sells a cake for $15.75. A customer pays with a $20 note. How much change is given?

Answer: 4.25

Question 12: Error analysis: A student subtracts 9.4 from 15.8 and gets 7.4. Identify the mistake and correct it.

Answer: The student subtracted incorrectly. 15.8 - 9.4 = 6.4. They may have misaligned decimals or miscalculated.