Primary 5 Mathematics Whole Numbers Quiz

Primary 5 Mathematics Quiz - Whole Numbers

Answer Key

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Section A: Place Value and Number Reading (Questions 1–5)

1.
Answer: 3,205,047
Working: Three million = 3,000,000; two hundred five thousand = 205,000; forty-seven = 47. Combine: 3,000,000 + 205,000 + 47 = 3,205,047.
Marking: 1 mark for correct numeral.

2.
Answer: 600,000
Working: The digit 6 is in the hundred thousands place. Value = 6 × 100,000 = 600,000.
Marking: 1 mark for correct value.

3.
Answer: Seven million, eighty thousand and ninety
Working: 7,000,000 + 80,000 + 90 = 7,080,090.
Marking: 1 mark for correct words.

4.
Answer: Hundred thousands
Working: In 5,340,127, the digit 3 is in the hundred thousands place.
Marking: 1 mark for correct place value.

5.
Answer: 2,045,000, 2,405,000, 2,450,000
Working: Compare digit by digit from left: 2,045,000 < 2,405,000 < 2,450,000.
Marking: 1 mark for correct order.

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Section B: Rounding and Estimation (Questions 6–10)

6.
Answer: 3,800,000
Working: The hundred thousands digit is 7. The next digit (ten thousands) is 8, which is ≥ 5, so round up. 3,784,521 → 3,800,000.
Marking: 2 marks for correct answer with working.

7.
Answer: 9,000,000
Working: The millions digit is 9. The next digit (hundred thousands) is 4, which is < 5, so round down. 9,456,312 → 9,000,000.
Marking: 2 marks for correct answer with working.

8.
Answer: 5,000
Working: The thousands digit is 4. The next digit (hundreds) is 6, which is ≥ 5, so round up. 4,678 → 5,000.
Marking: 2 marks for correct answer with working.

9.
Answer: 4,000,000
Working: 2,345,678 rounds to 2,000,000 (nearest million). 1,876,543 rounds to 2,000,000 (nearest million). Sum = 2,000,000 + 2,000,000 = 4,000,000.
Marking: 2 marks for correct answer with working.

10.
Answer: 6,500
Working: The hundreds digit is 4. The next digit (tens) is 9, which is ≥ 5, so round up. 6,499 → 6,500.
Marking: 2 marks for correct answer with working.

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Section C: Comparing and Ordering (Questions 11–15)

11.
Answer: 5,687,091
Working: Compare digit by digit: Both start with 5,6. Next digit: 7 < 8, so 5,687,091 is greater.
Marking: 2 marks for correct answer with working.

12.
Answer: >
Working: Compare digit by digit: 8,456,321 vs 8,456,231. First five digits same. Sixth digit: 3 > 2, so 8,456,321 > 8,456,231.
Marking: 2 marks for correct symbol.

13.
Answer: 1,243,657, 1,234,657, 1,234,567
Working: Compare digit by digit: 1,243,657 > 1,234,657 > 1,234,567.
Marking: 2 marks for correct order.

14.
Answer: 1,023,578
Working: Smallest 7-digit number: Use smallest non-zero digit first (1), then 0, then remaining digits in ascending order: 1,023,578.
Marking: 2 marks for correct answer with working.

15.
Answer: 9,764,310
Working: Largest 7-digit number: Arrange digits in descending order: 9,764,310.
Marking: 2 marks for correct answer with working.

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Section D: Operations and Word Problems (Questions 16–20)

16.
Answer: 6,913,568
Working:

  4,567,890
+ 2,345,678
-----------
  6,913,568

Marking: 3 marks for correct answer with working.

17.
Answer: 5,543,211
Working:

  9,000,000
- 3,456,789
-----------
  5,543,211

Marking: 3 marks for correct answer with working.

18.
Answer: 4,222,221
Working:

  2,345,678
+ 1,876,543
-----------
  4,222,221

Marking: 3 marks for correct answer with working.

19.
Answer: 2,222
Working:

  4,567
- 2,345
-------
  2,222

Marking: 3 marks for correct answer with working.

20.
Answer: 2,222,222
Working:

  3,456,789
- 1,234,567
-----------
  2,222,222

Marking: 3 marks for correct answer with working.

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Total Marks: 40