Primary 1 Mathematics Practice Paper 2

TuitionGoWhere Practice Paper - Mathematics Primary 1 — Answer Key

Paper: Practice Paper - Version 2 of 5 Topic: Numbers (Whole Numbers up to 100) Total Marks: 50

General marking notes: Accept neat handwriting and either numeral or word forms where asked. Award method marks even if the final answer is wrong, provided the working shows correct thinking.

Section A (Questions 1–5)

1. Answer: 68 (2 marks) Teaching note: "Sixty" means 6 tens (60). "Eight" means 8 ones. Put them together: $60 + 8 = 68$. Common mistake: Writing 86 (reversing tens and ones). Remind students the tens word ("sixty") always tells the first digit.

2. Answer: 90 (2 marks) Teaching note: In 95, the digit 9 is in the tens place. Its value is $9$ tens $= 90$. The digit 5 only means 5 ones. Common mistake: Answering 9. Ask: "Is the 9 worth 9 ones or 9 tens?"

3. Answer: 76 (2 marks) Method: Compare the tens digits first. 76 has 7 tens; 67 has 6 tens. Since $7 > 6$, then $76 > 67$. The ones digits never need checking because the tens already decide.

4. Answer: 43 (2 marks) Expected visual: 4 tens rods and 3 ones cubes, as specified in the image placeholder. Method: Count the rods: 4 tens $= 40$. Count the cubes: 3 ones $= 3$. Combine: $40 + 3 = 43$. Common mistake: Writing 34 (reading ones before tens). Always count tens first.

5. Answer: 37, 39 (2 marks) Method: The pattern goes up by 2 each time ($31 \to 33 \to 35$). So $35 + 2 = 37$ and $37 + 2 = 39$. Marking: 1 mark per correct blank.

Section B (Questions 6–15)

6. Answer: eighty-two (2 marks) Teaching note: 8 tens = "eighty", 2 ones = "two". Join them: eighty-two. Common mistakes: "eighty two" without hyphen is accepted; watch for "eighteen-two" confusion with teen numbers.

7. Answer: 60, 55 (2 marks) Method: Counting back by 5 means subtract 5 each time: $65 - 5 = 60$, then $60 - 5 = 55$. Check: $55 - 5 = 50$ matches the last given number. Marking: 1 mark per correct blank.

8. Answer: 5th (2 marks) Method: Ravi is 3rd. One place behind Ravi is 4th. Two places behind Ravi is 5th. So Mei Ling is 5th. Teaching note: Ordinal positions tell us order in a line: 1st, 2nd, 3rd, 4th, 5th. Common mistake: Answering 4th by counting only one person behind.

9. Answer: 44, 45, 54 (2 marks) Method: Compare tens digits first: 44 and 45 have 4 tens; 54 has 5 tens, so 54 is greatest. Then compare ones for 44 and 45: $4 < 5$, so 44 comes before 45. Order: $44, 45, 54$. Common mistake: Placing 54 first because "5 is small" — compare place by place, left to right.

10. Answer: 5 tens and 9 ones (2 marks) Teaching note: The first digit of a 2-digit number counts the tens; the second digit counts the ones. In 59: the 5 means 5 tens ($50$), the 9 means 9 ones ($9$). Check: $50 + 9 = 59$.

11. Answer: 57 (2 marks) Expected visual: 5 bundles of 10 sticks and 7 loose sticks, as specified in the image placeholder. Method: 5 bundles $\times\ 10 = 50$ sticks. Add the loose sticks: $50 + 7 = 57$ sticks. Teaching note: Bundling in tens is how we group numbers — 5 tens and 7 ones make 57.

12. Answer: 38, 48 (2 marks) Method: The pattern adds 10 each time ($8 \to 18 \to 28$). So $28 + 10 = 38$ and $38 + 10 = 48$. Teaching note: Adding 10 changes only the tens digit: 28 becomes 38. Marking: 1 mark per correct blank.

13. Answer: 3 (2 marks) Method: Think "50 and how many more make 53?" Count on from 50: 51, 52, 53 — that is 3 more. Or look at the ones digits: 53 has 3 ones, 50 has 0 ones, so the missing part is 3. Check: $50 + 3 = 53$. ✓

14. Answer: Greatest 88, Smallest 30 (2 marks) Method: All numbers have different tens digits: 3, 8, 8, 3. Compare tens first: 88 and 83 have 8 tens (greatest pair); 38 and 30 have 3 tens (smallest pair). Within each pair, compare ones: $88 > 83$, and $38 > 30$. So greatest = 88, smallest = 30. Marking: 1 mark for each correct value.

15. Answer: 36 (2 marks) Method: 10 more than 26: $26 + 10 = 36$. Check with the second clue: 10 less than 46: $46 - 10 = 36$. ✓ Both clues agree, so the number is 36. Teaching note: Adding or subtracting 10 changes only the tens digit (26 → 36 → 46).

Section C (Questions 16–20)

16. Answer: 64 bottle caps (4 marks) Step-by-step working:

1. 6 full groups of

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TuitionGoWhere Practice Paper - Mathematics Primary 1 — Answer Key

Paper: Practice Paper - Version 2 of 5 Topic: Numbers (Whole Numbers up to 100) Total Marks: 50

General marking notes: Accept neat handwriting and either numeral or word forms where asked. Award method marks even if the final answer is wrong, provided the working shows correct thinking.

Section A (Questions 1–5)

1. Answer: 68 (2 marks) Teaching note: "Sixty" means 6 tens (60). "Eight" means 8 ones. Put them together: $60 + 8 = 68$. Common mistake: Writing 86 (reversing tens and ones). Remind students the tens word ("sixty") always tells the first digit.

2. Answer: 90 (2 marks) Teaching note: In 95, the digit 9 is in the tens place. Its value is $9$ tens $= 90$. The digit 5 only means 5 ones. Common mistake: Answering 9. Ask: "Is the 9 worth 9 ones or 9 tens?"

3. Answer: 76 (2 marks) Method: Compare the tens digits first. 76 has 7 tens; 67 has 6 tens. Since $7 > 6$, then $76 > 67$. The ones digits never need checking because the tens already decide.

4. Answer: 43 (2 marks) Expected visual: 4 tens rods and 3 ones cubes, as specified in the image placeholder. Method: Count the rods: 4 tens $= 40$. Count the cubes: 3 ones $= 3$. Combine: $40 + 3 = 43$. Common mistake: Writing 34 (reading ones before tens). Always count tens first.

5. Answer: 37, 39 (2 marks) Method: The pattern goes up by 2 each time ($31 \to 33 \to 35$). So $35 + 2 = 37$ and $37 + 2 = 39$. Marking: 1 mark per correct blank.

Section B (Questions 6–15)

6. Answer: eighty-two (2 marks) Teaching note: 8 tens = "eighty", 2 ones = "two". Join them: eighty-two. Common mistakes: "eighty two" without hyphen is accepted; watch for confusion with teen numbers.

7. Answer: 60, 55 (2 marks) Method: Counting back by 5 means subtract 5 each time: $65 - 5 = 60$, then $60 - 5 = 55$. Check: $55 - 5 = 50$ matches the last given number. Marking: 1 mark per correct blank.

8. Answer: 5th (2 marks) Method: Ravi is 3rd. One place behind Ravi is 4th. Two places behind Ravi is 5th. So Mei Ling is 5th. Teaching note: Ordinal positions tell us order in a line: 1st, 2nd, 3rd, 4th, 5th. Common mistake: Answering 4th by counting only one person behind.

9. Answer: 44, 45, 54 (2 marks) Method: Compare tens digits first: 44 and 45 have 4 tens; 54 has 5 tens, so 54 is greatest. Then compare ones for 44 and 45: $4 < 5$, so 44 comes before 45. Order: $44, 45, 54$. Common mistake: Placing 54 first — compare place by place, left to right.

10. Answer: 5 tens and 9 ones (2 marks) Teaching note: In 59, the 5 means 5 tens ($50$), the 9 means 9 ones ($9$). Check: $50 + 9 = 59$.

11. Answer: 57 (2 marks) Expected visual: 5 bundles of 10 sticks and 7 loose sticks, as specified in the image placeholder. Method: 5 bundles $\times\ 10 = 50$ sticks. Add the loose sticks: $50 + 7 = 57$ sticks. Teaching note: Bundling in tens is how we group numbers — 5 tens and 7 ones make 57.

12. Answer: 38, 48 (2 marks) Method: The pattern adds 10 each time ($8 \to 18 \to 28$). So $28 + 10 = 38$ and $38 + 10 = 48$. Teaching note: Adding 10 changes only the tens digit: 28 becomes 38. Marking: 1 mark per correct blank.

13. Answer: 3 (2 marks) Method: Think "50 and how many more make 53?" Count on from 50: 51, 52, 53 — that is 3 more. Check: $50 + 3 = 53$. ✓

14. Answer: Greatest 88, Smallest 30 (2 marks) Method: Compare tens first: 88 and 83 have 8 tens (greatest pair); 38 and 30 have 3 tens (smallest pair). Within each pair compare ones: $88 > 83$, and $38 > 30$. So greatest = 88, smallest = 30. Marking: 1 mark for each correct value.

15. Answer: 36 (2 marks) Method: 10 more than 26: $26 + 10 = 36$. Check with the second clue: 10 less than 46: $46 - 10 = 36$. ✓ Both clues agree, so the number is 36. Teaching note: Adding or subtracting 10 changes only the tens digit (26 → 36 → 46).

Section C (Questions 16–20)

16. Answer: 64 bottle caps (4 marks) Step-by-step working:

1. 6 full groups of 10: $6 \times 10 = 60$
2. Add the extra caps: $60 + 4 = 64$

Answer statement: Jun Jie has 64 bottle caps altogether. Marking: 2 marks for correct method/working, 2 marks for correct final answer with units. Common mistake: Multiplying wrongly as $6 \times 4 = 24$. Encourage drawing 6 groups of 10 dots plus 4 extra dots.

17. (a) Answer: 97, 87, 80, 78 (2 marks) Method: Compare tens digits first: 97 has 9 tens (greatest), then 87 and 80 with 8 tens, then 78 with 7 tens. Between 87 and 80, compare ones: $7 > 0$, so 87 comes before 80. Order from greatest to smallest: $97, 87, 80, 78$. Marking: 2 marks for fully correct order; deduct 1 mark if order is reversed or one number misplaced.

(b) Answer: Nurul (1 mark) Nurul's score of 97 is the greatest because it has the most tens (9 tens).

(c) Answer: Priya (1 mark) Priya's score of 78 is the smallest because it has the fewest tens (7 tens).

18. Answer: 53 (4 marks) Step-by-step reasoning:

1. Ones digit = 3 (given).
2. Tens digit is 2 more than the ones digit: $3 + 2 = 5$.
3. Put the digits together: tens digit 5, ones digit 3 → 53.

Check: In 53, the ones digit is 3 ✓, and 5 is 2 more than 3 ✓. Answer statement: The number is 53. Marking: 2 marks for correct method shown, 2 marks for correct final answer. Common mistake: Adding 2 to the whole number instead of the digit (getting 28 or 55). Stress that "digit" means a single place value.

19. (a) Answer: 75, 70 (2 marks) Method: The numbers go down by 5 each time: $90 \to 85 \to 80$. So $80 - 5 = 75$ and $75 - 5 = 70$. Marking: 1 mark per correct blank.

(b) Answer: The rule is "count back by 5" / subtract 5 each time (2 marks) Accept any phrasing showing subtract 5: e.g., "Each number is 5 less than the one before," or "$-5$ every step." Marking: 2 marks for stating the rule correctly with the amount (5); award 1 mark if the student says "going down/backwards" without naming 5.

20. Answer: No (4 marks) Circle: No

Explanation: Siti counts in twos starting from 40: 40, 42, 44, 46, 48, 50, 52, ... All these numbers are even numbers. The number 51 is an odd number, so Siti will never say 51. Alternative explanation: Starting at 40 and adding 2 always keeps the ones digit even (0, 2, 4, 6, 8). The number 51 ends in 1, which is odd, so it cannot appear in the count.

Marking: 1 mark for circling No; 3 marks for a clear explanation showing understanding of the twos pattern (even numbers only). Common mistake: Saying Yes because 51 comes between 50 and 52. Remind students that skip-counting skips over some numbers — Siti jumps straight from 50 to 52.

Mark Scheme Summary

Total: 50 marks

— End of Answer Key —