Primary 2 Mathematics Money Quiz

Primary 2 Mathematics Quiz - Money: Answer Key

Total Marks: 40 (20 questions × 2 marks each)

---

Section A: Identifying and Writing Money Values

---

1. Write \5.60$ in cents.

Answer: 560 cents

Explanation:

• The dollar sign $$$ shows dollars, and the number after the decimal point shows cents.
• \5.60$ means 5 dollars and 60 cents.
• Since 1 dollar = 100 cents, we multiply: $5 \times 100 = 500$ cents.
• Then add the remaining cents: $500 + 60 = 560$ cents.
• Common mistake: Writing 5060 or just 56. Remember to convert dollars to cents properly.

Marks: 2

---

2. How many twenty-cent coins make \1.00$?

Answer: 5 coins

Explanation:

• \1.00 = 100$ cents.
• Each coin is worth 20 cents.
• We need to find how many 20s make 100: $20 + 20 + 20 + 20 + 20 = 100$, or $100 \div 20 = 5$.
• You can also count: 20, 40, 60, 80, 100 — that's 5 counts.
• Common mistake: Answering 20 (confusing the coin value with the quantity).

Marks: 2

---

3. Write 345 cents in dollars and cents.

Answer: \3.45$

Explanation:

• To convert cents to dollars and cents, we split into hundreds.
• 345 cents = 300 cents + 45 cents.
• Since 100 cents = \1$, we have:$300 \div 100 = 3$ dollars.
• The remaining 45 cents stays as cents.
• So 345 cents = \3.45$ (3 dollars and 45 cents).
• Key idea: The decimal point separates dollars from cents. Always write 2 digits after the decimal.

Marks: 2

---

4. Circle the greatest amount.

Answer: \3.05$ should be circled.

Explanation:

• First, convert everything to the same form for easy comparison. Let's use dollars and cents:
  • \2.75$ = 2 dollars 75 cents
  • 275 cents = \2.75$(since$275 \div 100 = 2$ remainder 75)
  • \2.50$ = 2 dollars 50 cents
  • 250 cents = \2.50$
  • \3.05$ = 3 dollars 5 cents
• Compare: \2.75$,$$2.75$,$$2.50$,$$2.50$,$$3.05$
• \3.05$ is greatest because 3 dollars is more than 2 dollars.
• Common mistake: Thinking 275 cents is more than \3.05$ because 275 looks bigger than 3. Always convert to same units!

Marks: 2

---

5. Fill in the blank: \4.80 = ______$ cents

Answer: 480 cents

Explanation:

• \4.80$ means 4 dollars and 80 cents.
• Convert dollars to cents: $4 \times 100 = 400$ cents.
• Add the remaining cents: $400 + 80 = 480$ cents.
• Shortcut: For dollars to cents, remove the dollar sign and decimal point. \4.80 \rightarrow$ move decimal: 480.

Marks: 2

---

Section B: Counting Money and Making Amounts

---

6. Mei Ling has these coins in her purse. How much money does she have altogether?

Expected image: Four Singapore coins: 50¢, 20¢, 20¢, 10¢

Answer: \1.00$ (or 100 cents)

Explanation:

• Add the values step by step:
  • 50 cents + 20 cents = 70 cents
  • 70 cents + 20 cents = 90 cents
  • 90 cents + 10 cents = 100 cents
• 100 cents = \1.00$
• Method tip: Group coins to make friendly numbers. 50 + 20 + 20 + 10: you could do 50 + 10 = 60, then 20 + 20 = 40, then 60 + 40 = 100.

Marks: 2

---

7. Raj wants to buy a notebook that costs \1.80$. He has one$$1$ coin and some twenty-cent coins. What is the fewest number of twenty-cent coins he needs?

Answer: 4 twenty-cent coins

Explanation:

• Cost of notebook: \1.80 = 180$ cents.
• Raj has: \1$ coin = 100 cents.
• Amount still needed: $180 - 100 = 80$ cents.
• Each twenty-cent coin is worth 20 cents.
• How many 20s in 80? $20 + 20 + 20 + 20 = 80$, or $80 \div 20 = 4$.
• Check: \1.00 + $0.80 = $1.80$ ✓
• "Fewest" means we want the smallest number of coins. Using four 20¢ coins is better than using eight 10¢ coins or other combinations.

Marks: 2

---

8. Complete the table.

Answer:

Dollars and Cents	Cents Only
\3.25$	325 cents
\7.00$	700 cents
\4.60$	460 cents

Explanation:

• First row: \3.25 \rightarrow$remove$$$ and decimal: 325 cents.
• Second row: \7.00 \rightarrow 7 \times 100 = 700$ cents.
• Third row: 460 cents $\rightarrow 460 \div 100 = 4$ remainder 60, so \4.60$.
• Pattern: Cents to dollars: divide by 100, put decimal point 2 places from right. Dollars to cents: multiply by 100, or remove decimal.

Marks: 2 (all three correct needed for full marks; 1 mark for two correct)

---

9. A sticker costs 60 cents. Sara has three 20-cent coins. Does she have enough money?

Answer: Yes

Explanation:

• Sara has: 3 × 20 cents = 60 cents.
• Sticker costs: 60 cents.
• Compare: $60$ cents $= 60$ cents.
• She has exactly enough. She does not have extra, but she does have enough.
• Note: "Enough" means ≥ (greater than or equal to), not just >.

Marks: 2 (1 mark for correct Yes/No, 1 mark for correct explanation or working)

---

10. What is the total value of: two \1$ notes + one 50-cent coin + three 10-cent coins?

Answer: \2.80$ (or 280 cents)

Explanation:

• Two \1$notes:$2 \times $1 = $2.00$
• One 50-cent coin: \0.50$
• Three 10-cent coins: $3 \times 10 = 30$ cents = \0.30$
• Total: \2.00 + $0.50 + $0.30 = $2.80$
• Step-by-step: Add dollars first: \2.00$. Then add cents: 50 + 30 = 80 cents. Final answer:$$2.80$.

Marks: 2

---

Section C: Addition and Subtraction of Money

---

11. \2.35 + $1.40 =$$______$

Answer: \3.75$

Working:

  $2.35
+ $1.40
-------
  $3.75

• Step 1: Add cents: 35 cents + 40 cents = 75 cents.
• Step 2: Add dollars: \2 + $1 = $3$.
• Step 3: Combine: \3.75$.
• Important: Line up the decimal points when adding. The answer has 2 digits after the decimal.

Marks: 2

---

12. Amy has \5.00$. She buys a pencil for$$1.25$. How much money does she have left?

Answer: \3.75$

Working:

  $5.00
- $1.25
-------
  $3.75

• Step 1: \5.00 = $4.00$+$$1.00 = $4.00$ + 100 cents
• Step 2: 100 cents - 25 cents = 75 cents
• Step 3: \4.00 - $1.00 = $3.00$
• Step 4: \3.00$+ 75 cents =$$3.75$

Or using decomposition:

• \5.00 - $1.00 = $4.00$
• \4.00 - $0.20 = $3.80$
• \3.80 - $0.05 = $3.75$

Marks: 2 (1 mark for correct method, 1 mark for correct answer)

---

13. Mr Tan buys a pen for \3.50$and a ruler for$$1.50$. He gives the shopkeeper$$10$. How much change does he receive?

Answer: \5.00$

Working:

• Step 1: Total cost = \3.50 + $1.50 = $5.00$
• Step 2: Change = \10.00 - $5.00 = $5.00$

  $3.50
+ $1.50
-------
  $5.00

 $10.00
- $5.00
-------
  $5.00

• Two-step problem: First find total spent, then subtract from amount given.

Marks: 2 (1 mark for total cost, 1 mark for final change)

---

14. \4.00 - $2.65 =$$______$

Answer: \1.35$

Working:

  $4.00
- $2.65
-------
  $1.35

• Step 1: \4.00 = $3.00$ + 100 cents
• Step 2: 100 cents - 65 cents = 35 cents
• Step 3: \3.00 - $2.00 = $1.00$
• Step 4: \1.00$+ 35 cents =$$1.35$

Or: \4.00 - $2.00 = $2.00$;$$2.00 - $0.65 = $1.35$

Marks: 2

---

15. Jill has \3.80$. Her brother gives her$$2.20$more. She then spends$$4.50$ on a book. How much money does Jill have in the end?

Answer: \1.50$

Working:

• Step 1: Money after receiving from brother: \3.80 + $2.20 = $6.00$
• Step 2: Money after buying book: \6.00 - $4.50 = $1.50$

  $3.80
+ $2.20
-------
  $6.00

  $6.00
- $4.50
-------
  $1.50

• Multi-step problem: Work through each event in order. Notice that \3.80 + $2.20$makes a friendly number$$6.00$because 80 + 20 = 100 cents =$$1.00$.

Marks: 2 (1 mark for intermediate step correct, 1 mark for final answer)

---

Section D: Word Problems and Real-Life Applications

---

16. Tom buys one exercise book and one pencil. How much does he spend altogether?

Expected image: Price list showing Exercise book = \1.20$, Pencil =$$0.80$

Answer: \2.00$

Working:

• Cost of exercise book: \1.20$
• Cost of pencil: \0.80$
• Total: \1.20 + $0.80 = $2.00$

  $1.20
+ $0.80
-------
  $2.00

• Note: 20 cents + 80 cents = 100 cents = \1.00$, so$$1 + $1 = $2$.

Marks: 2

---

17. Using the same price list, Mary has \2.00$. She buys an eraser. Can she buy a ruler with the money left?

Expected image: Price list showing Eraser = \0.50$, Ruler =$$1.00$

Answer: Yes

Working:

• Mary has: \2.00$
• Cost of eraser: \0.50$
• Money left: \2.00 - $0.50 = $1.50$
• Cost of ruler: \1.00$
• Compare: \1.50 > $1.00$, so yes, she can buy the ruler.
• She would have \0.50$ left after both purchases.

Marks: 2 (1 mark for correct Yes/No with working, 1 mark for correct comparison or explanation)

---

18. Mrs Lee buys 3 identical files for \6.00$ altogether. What is the cost of one file?

Answer: \2.00$

Working:

• 3 files cost \6.00$ total.
• Cost of one file = \6.00 \div 3 = $2.00$
• Check: \2.00 + $2.00 + $2.00 = $6.00$ ✓
• Concept: "Identical" means same price. Division shares the total equally.

Marks: 2

---

19. Ken saves 50 cents every day. How many days will he take to save \3.50$?

Answer: 7 days

Working:

• First, convert to same units: \3.50 = 350$ cents.
• Daily saving: 50 cents.
• Number of days = $350 \div 50 = 7$
• Or count: 50, 100, 150, 200, 250, 300, 350 — that's 7 steps.

Or in dollars:

• \0.50 \times 7 = $3.50$

Marks: 2

---

20. A muffin costs \1.60$. A cupcake costs 90 cents. What is the difference in their prices? (Give your answer in dollars and cents.)

Answer: \0.70$ or 70 cents

Working:

• Convert to same units: 90 cents = \0.90$
• Difference: \1.60 - $0.90 = $0.70$

  $1.60
- $0.90
-------
  $0.70

• Important: The question asks for "dollars and cents," so \0.70$ is preferred over just "70 cents," though both represent the same value.
• "Difference" means subtraction. Always subtract the smaller from the larger.

Marks: 2

---

End of Answer Key