Primary 5 Mathematics Practice Paper 2

TuitionGoWhere Practice Paper - Mathematics Primary 5 (Answer Key)

TuitionGoWhere Practice Paper (AI) — Version 2

Subject: Mathematics
Level: Primary 5
Paper: Practice Paper 2 (Whole Numbers Focus)
Total Marks: 50

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Section A: Multiple Choice Questions (10 marks)

1. In the number 4 728 391, which digit is in the ten thousands place? [2]

Answer: (2) 7

Explanation:
The place values from right to left are: ones, tens, hundreds, thousands, ten thousands, hundred thousands, millions.
In 4 728 391:

• 1 is in the ones place
• 9 is in the tens place
• 3 is in the hundreds place
• 8 is in the thousands place
• 2 is in the ten thousands place
• 7 is in the hundred thousands place
• 4 is in the millions place

Common mistake: Confusing ten thousands (5th digit from right) with hundred thousands (6th digit from right).

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2. Round 3 847 256 to the nearest hundred thousand. [2]

Answer: (3) 3 900 000

Explanation:
To round to the nearest hundred thousand, look at the ten thousands digit (4).
Since 4 < 5, we round down. The hundred thousands digit (8) stays the same, and all digits to the right become 0.
3 847 256 → 3 800 000? Wait, let me recheck.
3 847 256: The hundred thousands digit is 8. The ten thousands digit is 4.
Since 4 < 5, round down → 3 800 000.

Correction: The correct answer is (1) 3 800 000.
Let me verify: 3 847 256 rounded to nearest hundred thousand.
Hundred thousands place = 8 (value 800 000). Next digit (ten thousands) = 4.
Since 4 < 5, round down → 3 800 000.
Correct Answer: (1) 3 800 000

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3. Which of the following has the same value as 5 000 000 + 300 000 + 40 000 + 6 000 + 200 + 90 + 7? [2]

Answer: (1) 5 346 297

Explanation:
Add the place values:
5 000 000

• 300 000 = 5 300 000
• 40 000 = 5 340 000
• 6 000 = 5 346 000
• 200 = 5 346 200
• 90 = 5 346 290
• 7 = 5 346 297

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4. Find the value of 72 × (500 − 300) ÷ 12. [2]

Answer: (1) 1 200

Explanation:
Follow order of operations (BODMAS):

1. Brackets first: 500 − 300 = 200
2. Multiplication and division from left to right:
   72 × 200 = 14 400
   14 400 ÷ 12 = 1 200

Alternatively: 72 ÷ 12 = 6, then 6 × 200 = 1 200.

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5. A factory produced 2 450 toys on Monday. It produced 3 times as many toys on Tuesday as on Monday. How many toys did the factory produce on both days? [2]

Answer: (2) 9 800

Explanation:
Monday: 2 450 toys
Tuesday: 3 × 2 450 = 7 350 toys
Total: 2 450 + 7 350 = 9 800 toys

Common mistake: Only calculating Tuesday's production (7 350) and forgetting to add Monday's.

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Section B: Short Answer Questions (20 marks)

6. Write 6 080 405 in words. [2]

Answer: Six million eighty thousand four hundred and five

Explanation:
Break down by place value:

• 6 000 000 = Six million
• 80 000 = Eighty thousand (not eight thousand!)
• 400 = Four hundred
• 5 = Five

Note: The zero in the hundred thousands place means we don't say "hundred thousand". The zero in the thousands place is covered by "eighty thousand". The zero in the tens place is not spoken.

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7. What is the value of the digit 9 in the number 8 942 317? [2]

Answer: 900 000 (or nine hundred thousand)

Explanation:
In 8 942 317, the digit 9 is in the hundred thousands place.
Value = 9 × 100 000 = 900 000.

Common mistake: Writing "90 000" (ten thousands) or "9 000 000" (millions).

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8. Arrange the following numbers from the smallest to the greatest. [2]

4 208 391, 4 280 391, 4 028 391, 4 208 931

Answer: 4 028 391, 4 208 391, 4 208 931, 4 280 391

Explanation:
Compare digit by digit from the left (millions place):
All have 4 millions.
Compare hundred thousands: 0, 2, 2, 2 → 4 028 391 is smallest.
For the remaining three (all have 2 hundred thousands):
Compare ten thousands: 0, 0, 8 → 4 280 391 is greatest.
For 4 208 391 and 4 208 931: compare hundreds: 3 vs 9 → 4 208 391 < 4 208 931.

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9. Find the product of 3 428 and 27. [2]

Answer: 92 556

Working:

    3 4 2 8
  ×     2 7
  ---------
   2 3 9 9 6  (3 428 × 7)
+ 6 8 5 6 0   (3 428 × 20)
  ---------
   9 2 5 5 6

Check: 3 428 × 27 = 3 428 × (30 − 3) = 102 840 − 10 284 = 92 556 ✓

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10. Divide 8 736 by 16. [2]

Answer: 546

Working (Long Division):

      5 4 6
  1 6 | 8 7 3 6
      - 8 0
        7 3
      - 6 4
          9 6
        - 9 6
            0

Check: 546 × 16 = 546 × 10 + 546 × 6 = 5 460 + 3 276 = 8 736 ✓

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11. A number when rounded to the nearest thousand is 5 240 000. What is the greatest possible value of this number? [2]

Answer: 5 240 499

Explanation:
When rounding to the nearest thousand, we look at the hundreds digit.
For the rounded value to be 5 240 000, the number must be from 5 239 500 to 5 240 499.
The greatest possible value is 5 240 499 (since 5 240 500 would round up to 5 241 000).

Common mistake: Writing 5 240 999 or 5 240 000.

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12. Find the value of 4 500 × 600. [2]

Answer: 2 700 000

Explanation:
4 500 × 600 = (45 × 100) × (6 × 100) = (45 × 6) × 10 000 = 270 × 10 000 = 2 700 000.

Or: 4 500 × 600 = 4 500 × 6 × 100 = 27 000 × 100 = 2 700 000.

Tip: Count the zeros. 4 500 has 2 zeros, 600 has 2 zeros → answer has 4 zeros. 45 × 6 = 270, add 4 zeros → 2 700 000.

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13. A library has 4 872 fiction books. It has 1 358 more non-fiction books than fiction books. How many books are there in the library altogether? [2]

Answer: 11 102

Working:
Fiction books = 4 872
Non-fiction books = 4 872 + 1 358 = 6 230
Total = 4 872 + 6 230 = 11 102

Common mistake: Only finding non-fiction books (6 230) and forgetting to add fiction books.

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14. Mr Tan had $12 500. He spent$3 850 on a television and $1 920 on a washing machine. How much money had he left? [2]

Answer: $6 730

Working:
Total spent = $3 850 +$1 920 = $5 770 Money left =$12 500 − $5 770 =$6 730

Alternative: $12 500 −$3 850 = $8 650;$8 650 − $1 920 =$6 730.

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15. Complete the number pattern. [2]

2 500 000, 2 450 000, 2 400 000, __________, 2 300 000

Answer: 2 350 000

Explanation:
The pattern decreases by 50 000 each time:
2 500 000 − 50 000 = 2 450 000
2 450 000 − 50 000 = 2 400 000
2 400 000 − 50 000 = 2 350 000
2 350 000 − 50 000 = 2 300 000 ✓

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Section C: Structured / Long Answer Questions (20 marks)

16. A stadium has 8 450 seats. On Saturday, 5 680 seats were occupied. On Sunday, 1 240 more seats were occupied than on Saturday. [4]

(a) How many seats were occupied on Sunday?
Answer: 6 920

Working:
Saturday: 5 680 seats
Sunday: 5 680 + 1 240 = 6 920 seats

(b) How many seats were not occupied on both days altogether?
Answer: 4 280

Working:
Total seats over 2 days = 8 450 × 2 = 16 900
Total occupied = 5 680 + 6 920 = 12 600
Not occupied = 16 900 − 12 600 = 4 300? Wait, let me recalculate.

5 680 + 6 920 = 12 600.
16 900 − 12 600 = 4 300.

Correction: Answer is 4 300.

Alternative method:
Saturday empty = 8 450 − 5 680 = 2 770
Sunday empty = 8 450 − 6 920 = 1 530
Total empty = 2 770 + 1 530 = 4 300 ✓

Mark breakdown:

• (a) Correct answer with working: 1 mark
• (b) Correct method (total seats × 2 or empty seats per day): 1 mark
• (b) Correct calculation: 1 mark
• (b) Correct final answer: 1 mark

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17. A factory packed 6 720 bottles of juice into cartons. Each carton contained 24 bottles. [4]

(a) How many cartons were used?
Answer: 280

Working:
6 720 ÷ 24 = 280 cartons

Check: 280 × 24 = 280 × 20 + 280 × 4 = 5 600 + 1 120 = 6 720 ✓

(b) If each carton was sold for $18, how much money was collected from the sale of all the cartons?** **Answer:$5 040

Working:
280 × $18 = 280 × 10 + 280 × 8 = 2 800 + 2 240 =$5 040

Mark breakdown:

• (a) Correct division with working: 2 marks
• (b) Correct multiplication using answer from (a): 2 marks
  (If (a) is wrong but (b) correctly uses that wrong answer, award 1 mark for method)

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18. Mrs Lim bought 35 boxes of apples. There were 48 apples in each box. She threw away 127 rotten apples and packed the remaining apples into bags of 9. [4]

(a) How many apples did Mrs Lim buy altogether?
Answer: 1 680

Working:
35 × 48 = 35 × 50 − 35 × 2 = 1 750 − 70 = 1 680
Or: 35 × 48 = 30 × 48 + 5 × 48 = 1 440 + 240 = 1 680

(b) How many bags of apples did she pack?
Answer: 172 bags (with 5 apples left over, but question asks for bags packed)

Working:
Good apples = 1 680 − 127 = 1 553
Number of bags = 1 553 ÷ 9 = 172 remainder 5
So 172 full bags were packed.

Check: 172 × 9 = 1 548; 1 548 + 5 = 1 553 ✓

Mark breakdown:

• (a) Correct multiplication: 2 marks
• (b) Correct subtraction (total − rotten): 1 mark
• (b) Correct division and interpretation (whole bags only): 1 mark

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19. The sum of two numbers is 8 450. The difference between the two numbers is 1 280. Find the two numbers. [4]

Answer: 4 865 and 3 585

Working (Method 1 - Algebraic):
Let the larger number be x, smaller be y.
x + y = 8 450
x − y = 1 280
Add: 2x = 9 730 → x = 4 865
Then y = 8 450 − 4 865 = 3 585

Working (Method 2 - Model/Arithmetic):
Larger number = (Sum + Difference) ÷ 2 = (8 450 + 1 280) ÷ 2 = 9 730 ÷ 2 = 4 865
Smaller number = (Sum − Difference) ÷ 2 = (8 450 − 1 280) ÷ 2 = 7 170 ÷ 2 = 3 585
Or: Smaller = 8 450 − 4 865 = 3 585

Check: 4 865 + 3 585 = 8 450 ✓; 4 865 − 3 585 = 1 280 ✓

Mark breakdown:

• Correct method (formula or model): 2 marks
• Correct larger number: 1 mark
• Correct smaller number: 1 mark

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20. A school has 1 240 pupils. 3/8 of the pupils are boys. The rest are girls. [4]

(a) How many girls are there in the school?
Answer: 775

Working:
Number of boys = 3/8 × 1 240 = 1 240 ÷ 8 × 3 = 155 × 3 = 465
Number of girls = 1 240 − 465 = 775

Alternative: Girls = 5/8 × 1 240 = 1 240 ÷ 8 × 5 = 155 × 5 = 775

(b) If each girl donated $5 and each boy donated$3 to a charity, how much money was collected altogether?
Answer: $5 270

Working:
Girls' donation = 775 × $5 =$3 875
Boys' donation = 465 × $3 =$1 395
Total = $3 875 +$1 395 = $5 270

Mark breakdown:

• (a) Correct fraction calculation for boys or girls: 1 mark
• (a) Correct number of girls: 1 mark
• (b) Correct calculation for girls' donation: 1 mark
• (b) Correct calculation for boys' donation and total: 1 mark

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End of Answer Key