Primary 2 Mathematics Time Quiz

Primary 2 Mathematics Quiz - Time: Answer Key

Total Marks: 40

Teaching notes are included so a student new to telling time can learn the method, not just the answer. Key idea used throughout: 1 hour = 60 minutes.

Answer 1. (1 mark)

Answer: 60 minutes

This is a fact to remember: 1 hour is always made up of 60 minutes. Every conversion in this topic uses this fact.

Answer 2. (1 mark)

Answer: 3.40 (also accept 3:40)

Method:

• The short hour hand is between 3 and 4, so the hour is 3.
• The long minute hand points at the 8. Count in fives from the 12: 5, 10, 15, 20, 25, 30, 35, 40. So it is 40 minutes.
• Time shown: 3.40.

Common mistake: reading the minute hand at the 8 as "8 minutes". The numerals on a clock stand for fives when counting minutes.

Answer 3. (1 mark)

Answer: 120 minutes

Since 1 hour = 60 minutes, then 2 hours = 60 + 60 = 120 minutes.

Answer 4. (1 mark)

Answer: 30 minutes

Half an hour means half of 60 minutes. 60 ÷ 2

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Primary 2 Mathematics Quiz - Time: Answer Key

Total Marks: 40

Teaching notes are included so a student new to telling time can learn the method, not just the answer. Key idea used throughout: 1 hour = 60 minutes.

Answer 1. (1 mark)

Answer: 60 minutes

This is a fact to remember: 1 hour is always made up of 60 minutes. Every conversion in this topic uses this fact.

Answer 2. (1 mark)

Answer: 3.40 (also accept 3:40)

Method:

• The short hour hand is between 3 and 4, so the hour is 3.
• The long minute hand points at the 8. Count in fives from the 12: 5, 10, 15, 20, 25, 30, 35, 40. So it is 40 minutes.
• Time shown: 3.40.

Common mistake: reading the minute hand at the 8 as "8 minutes". The numerals on a clock stand for fives when counting minutes.

Answer 3. (1 mark)

Answer: 120 minutes

Since 1 hour = 60 minutes, then 2 hours = 60 + 60 = 120 minutes.

Answer 4. (1 mark)

Answer: 30 minutes

Half an hour means half of 60 minutes. 60 ÷ 2 = 30 minutes.

Answer 5. (1 mark)

Answer: Circle 100 minutes

Compare both times in minutes: 1 hour = 60 minutes, and 100 > 60. So 100 minutes is the longer time.

Common mistake: thinking "1 hour" is longer because 1 looks bigger than 100 as a number of units. Always convert to the same unit first.

Answer 6. (2 marks)

Answer: 85 min

Working:

• Split 1 h 25 min into hours and extra minutes: 1 h = 60 min, plus 25 min.
• 60 + 25 = 85 min.

Marks: 1 mark for correct method (changing 1 h to 60 min), 1 mark for the final answer 85.

Answer 7. (2 marks)

Answer: 2 h 10 min

Working:

• Take out groups of 60 minutes: 130 − 60 = 70, then 70 − 60 = 10.
• Two full groups of 60 were taken out, so that is 2 hours, with 10 minutes left over.
• 130 min = 2 h 10 min.

Check: 60 + 60 + 10 = 130. ✓

Answer 8. (2 marks)

(a) Answer: 11.52 (also accept 11:52)

• The hour hand is just before 12, so the hour is still 11.
• The minute hand is just before the 11 numeral, which stands for 55 minutes; two small marks before that gives 53... counting carefully, it points at 52 minutes past.
• Time shown: 11.52.

(b) Answer: 12.12 (noon)

Working:

• From 11.52, count on 8 minutes to reach 12.00.
• 20 − 8 = 12 more minutes after 12.00 gives 12.12.
• So 20 minutes later is 12.12 (midday).

Marks: 1 mark per part.

Answer 9. (2 marks)

(a) Answer: 195 min

• 3 h = 60 × 3 = 180 min; 180 + 15 = 195 min.

(b) Answer: 15

• 75 min = 60 min + 15 min = 1 h 15 min, so the blank is 15.

Marks: 1 mark per part.

Answer 10. (2 marks)

Answer: 8.55 a.m.

Working:

• Start at 8.20 a.m. Count on 35 minutes.
• 8.20 + 30 min = 8.50; then + 5 min = 8.55.
• The bus arrives at school at 8.55 a.m.

Alternative method: 8.20 + 40 min would be 9.00, which is 5 minutes too far, so subtract: 9.00 − 5 min = 8.55.

Answer 11. (2 marks)

Answer: 45 minutes

Working:

• From 6.45 p.m., count to the next whole hour: 6.45 → 7.00 is 15 minutes.
• From 7.00 to 7.30 is 30 minutes.
• Total: 15 + 30 = 45 minutes.

This "count up to the hour, then carry on" method avoids borrowing across the hour.

Answer 12. (2 marks)

(a) Answer: 4.07 (also accept 4:07)

• The hour hand has just moved past the 4, so the hour is 4.
• The minute hand is just past the 1 numeral; the 1 stands for 5 minutes, and about 2 small marks beyond gives 7 minutes.
• Time shown: 4.07.

(b) Answer: 3.42

Working:

• Go back 7 minutes from 4.07 to reach 4.00.
• Still need to go back 25 − 7 = 18 more minutes.
• 18 minutes before 4.00 is 3.42.
• So 25 minutes earlier is 3.42.

Marks: 1 mark per part.

Answer 13. (2 marks)

(a) Answer: 55 minutes

• Add the two activities: 40 + 15 = 55 minutes.

(b) Answer: Less than 1 hour.

• Explanation: 1 hour = 60 minutes, and 55 minutes is smaller than 60 minutes, so her total time is less than 1 hour. She is 5 minutes short of a full hour.

Marks: 1 mark per part; the explanation in (b) must mention 60 minutes to earn the mark.

Answer 14. (2 marks)

Answer: 7.15 a.m.

Working:

• Ravi arrives 15 minutes before 7.30 a.m., so subtract.
• 7.30 − 15 min: go back 30 minutes to 7.00, then forward 30 − 15 = 15 minutes gives 7.15.
• Or directly: half an hour before 7.30 is 7.00, and 15 minutes before 7.30 is halfway between 7.00 and 7.30, which is 7.15.
• Ravi arrives at 7.15 a.m.

Answer 15. (2 marks)

(a) Answer: 165 min

• 2 h = 120 min; 120 + 45 = 165 min.

(b) Answer: 3 h

• 180 ÷ 60 = 3, so 180 min = 3 h.

Marks: 1 mark per part.

Answer 16. (3 marks)

Answer: 5.35 p.m.

Working:

• Total homework time first: 25 + 20 = 45 minutes.
• From 4.50 p.m., count 10 minutes to reach 5.00.
• 45 − 10 = 35 minutes remain after 5.00.
• 5.00 + 35 min = 5.35 p.m.
• Mei Ling finishes her homework at 5.35 p.m.

Marks: 1 mark for finding total time (45 min), 1 mark for correct crossing of the hour, 1 mark for the final answer.

Answer 17. (3 marks)

Answer: 3.55 p.m.

Working:

• Add the whole hour first: 2.15 p.m. + 1 h = 3.15 p.m.
• Then add the 40 minutes: 3.15 + 40 min.
• 3.15 + 45 min would be 4.00, which is 5 minutes too much, so 3.15 + 40 min = 3.55 p.m.
• Or step by step: 3.15 → 3.45 is 30 min, then + 10 min = 3.55.
• The movie ends at 3.55 p.m.

Marks: 1 mark for adding the hour correctly, 1 mark for handling the minutes, 1 mark for the final answer.

Answer 18. (3 marks)

Answer: 1 h 25 min

Working:

• From 9.40 a.m., count up to the next whole hour: 9.40 → 10.00 is 20 minutes.
• From 10.00 to 11.05 is 1 h 5 min.
• Total duration: 20 min + 1 h 5 min = 1 h 25 min.
• Kai played at the playground for 1 h 25 min.

Check by working backwards: 11.05 minus 1 h = 10.05; 10.05 minus 25 min = 9.40. ✓

Marks: 1 mark for the gap to the hour (20 min), 1 mark for the remaining span, 1 mark for the final answer in hours and minutes.

Answer 19. (3 marks)

Answer: Yes, both trains arrive at 9.10 a.m.

Working:

• Train A: 7.50 a.m. + 1 h = 8.50 a.m.; 8.50 + 20 min = 9.10 a.m.
• Train B: 8.05 a.m. + 1 h = 9.05 a.m.; 9.05 + 5 min = 9.10 a.m.
• Both trains arrive at 9.10 a.m., so yes, they arrive at their destination at the same time.

Explanation: Even though Train B leaves later, its journey is shorter by exactly the same amount of time that it left later (15 minutes), so the arrival times match.

Marks: 1 mark for each train's correct arrival time, 1 mark for the conclusion with explanation.

Answer 20. (3 marks)

(a) Answer: 50 minutes

• Add all three parts: 15 + 20 + 15 = 50 minutes.

(b) Answer: 7.20 p.m.

Working:

• Father leaves home at 6.30 p.m. and is away for 50 minutes.
• 6.30 + 30 min = 7.00; then + 20 min = 7.20.
• Father reaches home at 7.20 p.m.

Marks: 1 mark for part (a); 2 marks for part (b) working and final answer.

End of Answer Key