Primary 2 Mathematics Length Quiz

Primary 2 Mathematics Quiz - Length: Answer Key

Total Marks: 50

Answer 1. (1 mark)

Answer: m

Teaching note: An abbreviation is a short way of writing a word. "Metre" is always shortened to a small letter m. Common mistakes: writing "M", "mt" or "mtr" — only lowercase "m" is correct.

Answer 2. (1 mark)

Answer: metres (m)

Teaching note: A door is tall, so we measure it in metres. Grams measure how heavy something is and litres measure liquid, so they cannot describe height. Always pair a number with a sensible unit.

Answer 3. (1 mark)

Answer: True ✓

Teaching note: The metre (m) is the standard unit for length in Primary 2. Length tells us how long or how tall something is, so the statement is true.

Answer 4. (1 mark)

Answer: Ribbon Q (9 m)

Teaching note: Both ribbons use the same unit (m), so compare the numbers directly: 9 is greater than 4, so 9 m is longer. Common mistake: choosing the smaller number or forgetting to check the units match first.

Answer 5. (1 mark)

Answer: (a) 10 m

Teaching note: Estimate by thinking of real objects. A bus is about as long as 5 cars, so 10 m is sensible. 100 m is about the length of a football field, and 1000 m is 1 km — far too long for a bus. Choosing the "most sensible" answer means picking the size that matches real life.

Answer 6. (2 marks)

Answers: (a) < (b) =

Method: The units are the same (m), so compare the numbers. (a) 5 is less than 9, so 5 m < 9 m. (b) 12 and 12 are the same number with the same unit, so 12 m = 12 m. Award 1 mark per correct symbol.

Answer 7. (2 marks)

Answer: 1 m, 3 m, 5 m, 7 m

Method: All lengths use the same unit, so order the numbers from smallest to biggest: 1, 3, 5, 7. Common mistake: copying the numbers in the order given instead of comparing them first.

Answer 8. (2 marks)

Answer: 11 m

Working: "Longer than" means add. 8 m + 3 m = 11 m.

Teaching note: When one length is described as "longer than" another, start with the known length and add the extra amount. Marking: 1 mark for correct operation (+), 1 mark for correct answer with unit.

Answer 9. (2 marks)

Answer: 7 m

Method: The rope starts at 0 m and ends at the 7 m mark on the tape, so its length is 7 m. Expected visual: tape numbered 0 m to 10 m with the rope ending exactly at 7 m. Teaching note: when measuring from 0, the length equals the number at the end point. Common mistake: counting the starting mark as part of the length.

Answer 10. (2 marks)

Answer: 6 m

Working: Cutting off means taking away. 10 m − 4 m = 6 m.

Teaching note: "Cut off" tells us to subtract the piece removed from the whole length. Marking: 1 mark for subtraction shown, 1 mark for 6 m.

Answer 11. (3 marks)

Answer: 43 m

Working: Total means add both strings. 25 m + 18 m = 43 m.

• Step 1: Ones: 5 + 8 = 13. Write 3, carry 1 ten.
• Step 2: Tens: 2 + 1 + 1 carried = 4 tens.
• Step 3: Answer 43 m.

Marking: 1 mark for choosing addition, 1 mark for correct calculation, 1 mark for answer with unit. Common mistake: forgetting to regroup the 13 ones.

Answer 12. (3 marks)

Answer: 27 m

Working:

• Step 1: Find how far Ali has walked: 35 m + 28 m = 63 m.
• Step 2: Subtract from the whole track: 90 m − 63 m = 27 m.

Marking: 1 mark for adding both parts walked, 1 mark for subtracting from 90, 1 mark for 27 m. Common mistake: subtracting only one of the two distances walked.

Answer 13. (3 marks)

Answers: (a) Carl (b) 6 m

Method: Read the table: Amir 12 m, Bella 9 m, Carl 15 m.

• (a) Compare the distances: 15 is the greatest, so Carl threw farthest. (1 mark)
• (b) Difference means subtract: 15 m − 9 m = 6 m. (2 marks: 1 for working, 1 for answer)

Expected visual: table with rows Amir 12 m, Bella 9 m, Carl 15 m. Teaching note: "how much farther" always means subtract the smaller distance from the larger one.

Answer 14. (3 marks)

Answer: (a) 8 m

Explanation points (award up to 2 marks):

• 80 m is about ten classrooms placed end to end — no single room is that long.
• 800 m is about the length of ten football fields — far too long.
• A classroom is roughly 8 long strides across, so 8 m matches real life.

Marking: 1 mark for circling 8 m, 2 marks

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Primary 2 Mathematics Quiz - Length: Answer Key

Total Marks: 50

Answer 1. (1 mark)

Answer: m

Teaching note: "Metre" is shortened to lowercase m. Common mistakes: writing "M", "mt" or "mtr".

Answer 2. (1 mark)

Answer: metres (m)

Teaching note: A door is tall, so we measure it in metres. Always pair a number with a sensible unit.

Answer 3. (1 mark)

Answer: True ✓

Teaching note: The metre (m) measures how long or how tall things are, so the statement is true.

Answer 4. (1 mark)

Answer: Ribbon Q (9 m)

Teaching note: Same unit (m), so compare numbers directly: 9 > 4, so Ribbon Q is longer.

Answer 5. (1 mark)

Answer: (a) 10 m

Teaching note: A bus is about as long as 5 cars, so 10 m is sensible. 100 m is a football field's length; 1000 m is far too long for a bus.

Answer 6. (2 marks)

Answers: (a) < (b) =

Method: Same unit, so compare numbers. (a) 5 < 9, so 5 m < 9 m. (b) 12 m = 12 m. Award 1 mark per correct symbol.

Answer 7. (2 marks)

Answer: 1 m, 3 m, 5 m, 7 m

Method: Order the numbers smallest to biggest: 1, 3, 5, 7. Common mistake: copying the given order without comparing.

Answer 8. (2 marks)

Answer: 11 m

Working: "Longer than" means add: 8 m + 3 m = 11 m.

Marking: 1 mark for correct operation (+), 1 mark for correct answer with unit.

Answer 9. (2 marks)

Answer: 7 m

Method: The rope starts at 0 m and ends at the 7 m mark, so its length is 7 m. Teaching note: when measuring from 0, the length equals the end-point number. Common mistake: counting the start mark as part of the length.

Answer 10. (2 marks)

Answer: 6 m

Working: Cutting off means subtracting: 10 m − 4 m = 6 m.

Marking: 1 mark for subtraction shown, 1 mark for 6 m with unit.

Answer 11. (3 marks)

Answer: 43 m

Working: Total means add: 25 m + 18 m = 43 m.

• Step 1: Ones: 5 + 8 = 13. Write 3, carry 1 ten.
• Step 2: Tens: 2 + 1 + 1 carried = 4 tens.
• Step 3: Answer 43 m.

Marking: 1 mark for choosing addition, 1 mark for correct calculation, 1 mark for answer with unit. Common mistake: forgetting to regroup the 13 ones.

Answer 12. (3 marks)

Answer: 27 m

Working:

• Step 1: Distance walked so far: 35 m + 28 m = 63 m.
• Step 2: Remaining distance: 90 m − 63 m = 27 m.

Marking: 1 mark for adding both parts walked, 1 mark for subtracting from 90, 1 mark for 27 m. Common mistake: subtracting only one walked distance.

Answer 13. (3 marks)

Answers: (a) Carl (b) 6 m

Method: Read the table: Amir 12 m, Bella 9 m, Carl 15 m.

• (a) Compare distances: 15 is greatest, so Carl threw farthest. (1 mark)
• (b) Difference means subtract: 15 m − 9 m = 6 m. (2 marks: 1 working, 1 answer)

Teaching note: "How much farther" always means subtract the smaller distance from the larger one.

Answer 14. (3 marks)

Answer: (a) 8 m

Explanation points (award up to 2 marks):

• 80 m is about ten classrooms end to end — no single room is that long.
• 800 m is about ten football fields — far too long.
• A classroom is roughly 8 long strides across, so 8 m matches real life.

Marking: 1 mark for circling 8 m, up to 2 marks for a sensible explanation of why the other lengths are not reasonable.

Answer 15. (3 marks)

Answers: (a) 30 m (b) 5 m

Working:

• (a) Joined plank: 14 m + 16 m = 30 m. (2 marks: 1 working, 1 answer)
• (b) More needed: 35 m − 30 m = 5 m. (1 mark)

Marking: Accept either order of steps; both subparts must show subtraction/addition correctly with units.

Answer 16. (4 marks)

Answer: 16 m

Working:

• Step 1: Total cut off: 15 m + 17 m = 32 m.
• Step 2: Wire left: 48 m − 32 m = 16 m.

Marking: 1 mark for adding the two cuts, 1 mark for subtracting from 48, 1 mark for correct calculation, 1 mark for answer with unit. Common mistake: subtracting only one day's cut.

Answer 17. (4 marks)

Answers: (a) Path D, Path B, Path A, Path C (b) 18 m

Working:

• (a) Compare lengths: D 40 m, B 31 m, A 22 m, C 22 m. Longest to shortest: Path D, Path B, then Path A and Path C (equal). (2 marks)
• (b) Difference: 40 m − 22 m = 18 m. (2 marks: 1 working, 1 answer)

Expected visual: bars labelled Path A 22 m, Path B 31 m, Path C 22 m, Path D 40 m, with A and C drawn equal. Teaching note: when two lengths are equal, they sit side by side in the order.

Answer 18. (4 marks)

Answers: (a) 34 m (b) 6 m

Working:

• (a) Total: 12 m + 9 m + 13 m = 34 m. (2 marks)
• (b) More needed: 40 m − 34 m = 6 m. (2 marks)

Marking: 1 mark per correct operation shown, 1 mark per correct answer with unit. Common mistake: adding only two of the three ribbons.

Answer 19. (4 marks)

Answers: (a) 20 m (b) 4 ropes

Working:

• (a) 4 ropes of 5 m: 5 m × 4 = 20 m (or 5 + 5 + 5 + 5 = 20 m). (2 marks)
• (b) 20 m ÷ 5 m = 4 skipping ropes. (2 marks)

Marking: 1 mark per correct method, 1 mark per correct answer with unit. Teaching note: repeated addition may replace multiplication at this level.

Answer 20. (4 marks)

Answers: (a) 1 m (b) 5 m (c) Priya

Working:

• (a) Kumar jumped 2 m less than Jia: 3 m − 2 m = 1 m. (1 mark)
• (b) Priya jumped 4 m more than Kumar: 1 m + 4 m = 5 m. (2 marks: 1 working, 1 answer)
• (c) Compare: Jia 3 m, Kumar 1 m, Priya 5 m. Priya jumped the farthest. (1 mark)

Teaching note: "Less than" means subtract; "more than" means add. Encourage pupils to list all three jumps before comparing.