Primary 4 Mathematics Practice Paper 4

TuitionGoWhere Practice Paper - Mathematics Primary 4

Answer Key — Version 4 of 5

Total Marks: 50

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Section A (20 marks)

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Question 1 (1 mark)

Answer: Seventy-three thousand, five hundred and eight.

Explanation:

• 73,000 = seventy-three thousand
• 500 = five hundred
• 8 = eight
• Note: We say "and" between the hundreds and the units when there are no tens, or use "and" before the last two digits in formal British English usage common in Singapore.

Marking: 1 mark for correct wording. Deduct ½ mark for "seventy-three thousand five hundred eight" (missing "and") or similar minor errors.

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Question 2 (1 mark)

Answer: 90,000 (or 9 ten thousands)

Explanation: The digit 9 is in the ten thousands place. In a 5-digit number, the places from left to right are: ten thousands, thousands, hundreds, tens, ones.

• Position: 9 | 1 | 4 | 2 | 6
• Place: ten thousands | thousands | hundreds | tens | ones

So the digit 9 represents 9 × 10,000 = 90,000.

Common mistake: Saying "9" or "9 thousands" — the digit 9 is not the same as its place value.

Marking: 1 mark for "90,000" or "9 ten thousands" or equivalent.

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Question 3 (1 mark)

Answer: 20,358

Explanation: To form the smallest 5-digit number:

• The first digit (ten thousands place) cannot be 0, or it would be a 4-digit number.
• Use the next smallest digit for the first place: 2
• Arrange the remaining digits in ascending order: 0, 3, 5, 8
• Result: 2 0 3 5 8 = 20,358

Common mistake: 02,358 (not a valid 5-digit number) or 23,058 (not the smallest possible).

Marking: 1 mark for correct answer.

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Question 4 (2 marks)

Answer: Missing number: 12,650; Rule: Add 100 each time (or "increase by 100")

Working:

• 12,550 − 12,450 = 100
• 12,550 + 100 = 12,650 ✓
• 12,650 + 100 = 12,750 ✓

Marking: 1 mark for correct missing number; 1 mark for correct rule.

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Question 5 (2 marks)

Answer:

• Nearest thousand: 86,000
• Nearest hundred: 86,400

Working for nearest thousand:

• 86,437: the thousands digit is 6, look at the hundreds digit (4)
• 4 < 5, so round down: 86,000

Working for nearest hundred:

• 86,437: the hundreds digit is 4, look at the tens digit (3)
• 3 < 5, so round down: 86,400

Marking: 1 mark each.

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Question 6 (2 marks)

(a) Answer: ArtScience Museum

Working: 38,156 rounded to nearest thousand: look at hundreds digit (1), 1 < 5, so round down to 38,000, which is about 40,000? No — check again.

• 38,156: hundreds digit is 1, so 38,156 → 38,000

Wait — re-reading: "about 40,000" suggests rounding to nearest ten thousand or the question uses "about" loosely.

• 38,156 to nearest ten thousand: thousands digit is 8, so 8 ≥ 5, round up to 40,000 ✓

Or: 45,093 → 45,000 (nearest thousand), 52,847 → 53,000.

Actually, checking all to nearest thousand: 52,847 → 53,000; 38,156 → 38,000; 45,093 → 45,000.

To nearest ten thousand: 52,847 → 50,000; 38,156 → 40,000; 45,093 → 50,000.

So ArtScience Museum rounds to 40,000 when rounded to nearest ten thousand.

Acceptable answer: ArtScience Museum with either rounding justification.

(b) Answer: 14,691 visitors

Working:

• Highest: National Museum at 52,847
• Lowest: ArtScience Museum at 38,156
• Difference: 52,847 − 38,156 = 14,691

Marking: 1 mark each part.

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Question 7 (2 marks)

(a) Answer: 63,092 < 63,902

Explanation: Compare digit by digit from left: both have 6 ten thousands, 3 thousands. Then 0 hundreds < 9 hundreds.

(b) Answer: 10,000 + 4,000 + 800 + 30 = 14,830 > 14,803 (or 14,830 > 14,803)

Explanation: 10,000 + 4,000 + 800 + 30 = 14,830. Compare with 14,803: 14,830 has 30 in tens/ones, while 14,803 has 03. So 14,830 > 14,803.

Marking: 1 mark each.

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Question 8 (2 marks)

Answer: 6,515 students

Working: 4,568 + 1,947 = 6,515

  4 5 6 8
+ 1 9 4 7
---------
  6 5 1 5

• Ones: 8 + 7 = 15 (write 5, carry 1)
• Tens: 6 + 4 + 1 = 11 (write 1, carry 1)
• Hundreds: 5 + 9 + 1 = 15 (write 5, carry 1)
• Thousands: 4 + 1 + 1 = 6

Marking: 2 marks for correct answer with working, or 1 mark for correct method with calculation error.

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Question 9 (2 marks)

Answer: 1,410 stickers

Working: 8,460 ÷ 6 = 1,410

    1 4 1 0
  _______
6 | 8 4 6 0
    6
   ---
    2 4
    2 4
   ----
      0 6
      0 6
     ----
        0 0
        0 0
       ----
          0

Or: 8,400 ÷ 6 = 1,400; 60 ÷ 6 = 10; so 1,400 + 10 = 1,410.

Marking: 2 marks for correct answer with working shown.

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Question 10 (2 marks)

Answer: 147 tins (with remainder, but since they need to pack all brownies: need 146 full tins and 1 tin with 24, or 147 tins needed)

Working: 5,280 ÷ 36 = 146 remainder 24

    1 4 6
  ______
36| 5 2 8 0
    3 6
   ----
    1 6 8
    1 4 4
   ------
      2 4 0
      2 1 6
     ------
         24

Since 24 brownies must also be packed (even if not full), they need 146 + 1 = 147 tins.

Marking: 2 marks for 147 with correct reasoning, or 146 with working shown but incorrect interpretation (1 mark).

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Section B (20 marks)

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Question 11 (3 marks)

(a) Answer: 35,000 (accept 34,000 to 36,000 if reading from approximate position; exact intended: 35,000)

Explanation: Point A is located halfway between 30,000 and 40,000, representing 35,000.

(b) Answer: Nearer to 70,000

Explanation:

• Distance to 60,000: 68,000 − 60,000 = 8,000
• Distance to 70,000: 70,000 − 68,000 = 2,000
• Since 2,000 < 8,000, 68,000 is nearer to 70,000.

Marking: (a) 1 mark; (b) 1 mark for correct choice, 1 mark for explanation with numbers.

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Question 12 (3 marks)

Answer: 10,575 more toys

Working:

• 2024 production: 93,576 + 15,849 = 109,425
• Toys needed in 2025: 120,000
• Difference: 120,000 − 109,425 = 10,575

  9 3 5 7 6
+ 1 5 8 4 9
-----------
 1 0 9 4 2 5

  1 2 0 0 0 0
-  1 0 9 4 2 5
  -----------
      1 0 5 7 5

Marking: 1 mark for 2024 production; 1 mark for correct subtraction set up; 1 mark for final answer.

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Question 13 (3 marks)

Answer: $595

Working:

• Total spent: $2,340 +$1,875 = $4,215
• Remaining: $8,500 −$4,215 = $4,285
• More needed: $980 −$4,285 = −$3,305 — she has enough!

Wait, re-reading: "How much more money does she need?" for the printer.

Actually: $4,285 remaining, printer costs$980. She has enough! So she needs $0 more, or the question assumes she hasn't bought it yet.

Re-interpreting: She has $8,500. Spends$2,340 + $1,875 =$4,215. Left: $4,285. Printer costs$980. She has enough.

So answer: She needs $0 more** or **She does not need more money; she has$4,285 and the printer costs $980, leaving her with$3,305.

But likely intended: Total wanted = $2,340 +$1,875 + $980 =$5,195. She has $8,500. She has enough.

Alternative reading: She spent on laptop and tablet, wants to know if she can afford printer.

Revised answer: She does not need more money. She has $8,500 −$2,340 − $1,875 =$4,285 remaining. The printer costs $980, which is less than$4,285.

However, if question intends "how much more to afford all three": $5,195 −$8,500 = she has enough.

Given wording ambiguity, most likely intended answer: She has enough; needs **$0** (or credit$3,305 remaining after all purchases).

Marking flexibility: Award marks for correct financial reasoning shown.

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Question 14 (4 marks)

(a) Answer:

Town	Population to nearest 10,000
Woodvale	50,000
Riverdale	50,000
Meadowbrook	40,000
Sunset Ridge	60,000

Working:

• 47,856: thousands digit 7 ≥ 5, round up → 50,000
• 52,143: thousands digit 2 < 5, round down → 50,000
• 38,927: thousands digit 8 ≥ 5, round up → 40,000
• 56,281: thousands digit 6 ≥ 5, round up → 60,000

(b) Answer: Estimated total: 200,000

Working: 50,000 + 50,000 + 40,000 + 60,000 = 200,000

Marking: (a) ½ mark each correct entry; (b) 1 mark for correct method, 1 mark for answer.

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Question 15 (4 marks)

(a) Answer: 9,400 books

(b) Answer: May

(c) Answer: Yes, they reached their goal. Total = 49,900 books... wait, recalculate:

8,500 + 6,200 + 9,400 + 7,800 + 11,200 + 5,600 = 48,700

Actually: 8,500 + 6,200 = 14,700

• 9,400 = 24,100
• 7,800 = 31,900
• 11,200 = 43,100
• 5,600 = 48,700

48,700 < 50,000, so No, they did not reach their goal. They were short by 1,300 books.

Working shown: Summing all six values = 48,700. 48,700 < 50,000.

Marking: (a) 1 mark; (b) 1 mark; (c) 1 mark for correct method, 1 mark for correct conclusion with comparison.

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Question 16 (3 marks)

(a) Answer: 7,450

Explanation: For rounding to nearest hundred to give 7,500, the number must be ≥ 7,450 (since 7,450 rounds up to 7,500).

(b) Answer: 7,549

Explanation: The number must be < 7,550 (since 7,550 would round to 7,600). So maximum is 7,549.

(c) Answer: No, 7,459 is not possible.

Explanation: 7,459 rounded to nearest hundred: look at tens digit (5). Since 5 ≥ 5, round up: 7,459 → 7,500. Wait — 7,459 DOES round to 7,500!

Let me recheck: 7,459. Hundreds digit is 4. Tens digit is 5. So 5 ≥ 5, round up: 4 becomes 5, giving 7,500. So Yes, 7,459 is possible!

Wait, but my range was 7,450 to 7,549. 7,459 is in this range. So yes, it is possible.

Corrected (c) Answer: Yes, 7,459 is possible.

7,459 rounded to nearest hundred: tens digit is 5, so round up the hundreds digit 4 → 5, giving 7,500. ✓

Marking: (a) 1 mark; (b) 1 mark; (c) 1 mark with correct explanation.

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Section C (10 marks)

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Question 17 (4 marks)

(a) Answer: 18.45 km (or 18 km 450 m)

Working: 18,450 ÷ 1,000 = 18.450 = 18.45 km

(b) Answer: 43.13 km or 43 km 130 m

Working:

• Tampines to Sengkang to Jurong West: 18,450 + 24,680 = 43,130 m = 43.13 km = 43 km 130 m

(c) Answer: Yes, he is correct.

Working:

• Via Sengkang: 43,130 m = 43.13 km
• Direct: 31,250 m = 31.25 km
• Difference: 43.13 − 31.25 = 11.88 km

11.88 km > 10 km, so yes, more than 10 km shorter.

Marking: (a) 1 mark; (b) 1 mark for correct addition, 1 mark for correct conversion; (c) 1 mark with working.

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Question 18 (3 marks)

Answer: 1,560 books per full shelf; short by 1,560 books for 6th shelf (i.e., 0 books on 6th, all 6 shelves would need 9,360)

Wait, re-reading: 12,480 ÷ 8 = 1,560 exactly. So 5 shelves = 7,800 books. Remaining = 12,480 − 7,800 = 4,680. That's enough for 3 more shelves!

Re-interpreting: Perhaps she wants 8 shelves full, or the problem has different numbers.

Given numbers: 12,480 books, 8 shelves equally = 1,560 per shelf. After 5 shelves (7,800 books), remaining 4,680 = exactly 3 more shelves. All 8 shelves full.

Perhaps intended: 12,480 books, arrange on shelves with about 8 shelves, or different number.

Actually re-reading: "After filling 5 shelves completely, she finds that the remaining books are not enough for the 6th shelf." This contradicts 12,480 ÷ 8 = 1,560 exactly.

Unless: "equally on 8 shelves" means she wants 8 shelves but may not have enough, or the problem meant to say different numbers.

Given the problem as stated: 12,480 ÷ 8 = 1,560, but this doesn't match the scenario.

Alternative interpretation: She fills shelves with some number, not necessarily 8 shelves full. Perhaps "8 shelves" is maximum.

Given contradiction, solving as intended: If after 5 shelves full, 6th is not full:

Books per shelf = 12,480 ÷ 8 = 1,560 (target). 5 shelves = 7,800. Remaining = 4,680. But 4,680 > 1,560, so 6th shelf CAN be filled.

Problem seems inconsistent. Assuming typo in source numbers, if we proceed:

If books were e.g., 7,860: 5 × 1,560 = 7,800, remaining 60, short by 1,500.

Given actual numbers, books per full shelf = 1,560, and there are actually 3 more full shelves, not "not enough."

Practical marking: Award marks for correct division 12,480 ÷ 8 = 1,560. Note inconsistency in problem, or accept that all 8 shelves can be filled.

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Question 19 (3 marks)

(a) Answer: $113.20 (verification)

Working:

• Rice: 2 × $18.50 =$37.00
• Oil: 3 × $8.90 =$26.70
• Noodles: 5 × $4.50 =$22.50
• Biscuits: 4 × $6.75 =$27.00

Total: $37.00 +$26.70 + $22.50 +$27.00 = $113.20 ✓

(b) Answer: $6.80

Working: $120.00 −$113.20 = $6.80

(c) Answer: No, she does not have enough.

Working:

• 10 packs of noodles: 10 × $4.50 = **$45.00**
• Change received: $6.80
• $6.80 <$45.00

She is short by $45.00 −$6.80 = $38.20

Marking: 1 mark each part.

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Total Marks Summary

Section	Marks
Section A	20
Section B	20
Section C	10
Total	50