Chapter 13.3 (Mathematics 5)

Arithmethic with Time. Addition

Addition of minutes and seconds

Group Activity 5

In groups of five:

  1. Take two different periods of time in minutes and seconds.
  2. Add the two periods of time.
  3. Study your method and answer the questions below:
    1. Which units of time are added first?
    2. How is a sum of more than 60s written?
    3. What happens to the minutes when the seconds are more than 60?
  4. Discuss and share your results with other groups.

Example 3a

Work out 25 minutes 15 seconds + 20 minutes 40 seconds.

minutes seconds 25 15 + 20 40 45 55

Example 3b

Work out 30 minutes 35 seconds + 14 minutes 28 seconds

minutes seconds 30 35 + 14 28 45 03

  1. 35 seconds + 28 seconds = 63 seconds
  2. Regroup 63 seconds into 1 minutes 3 seconds
  3. 30 minutes + 14 minutes = 44 minutes
  4. Add 1 minutes to 44 minutes to get 45 minutes

Exercise E

a) minutes seconds 7 20 + 8 35

b) minutes seconds 12 35 + 16 19

c) minutes seconds 36 47 + 29 49

a) minutes seconds 12 37 + 19 48

b) minutes seconds 15 43 + 20 20

c) minutes seconds 25 56 + 29 45

  1. 22 minutes 40 seconds + 16 minutes 10 seconds =
    =  minutes  seconds
  2. 28 minutes 24 seconds + 18 minutes 32 seconds =
    =  minutes  seconds
  3. 35 minutes 45 seconds + 20 minutes 35 seconds =
    =  minutes  seconds
  4. 31 minutes 38 seconds + 15 minutes 49 seconds =
    =  minutes  seconds

Answer. The total time taken was  minutes  seconds.

Answer. Total time was  minutes  seconds.

Answer. The two lessons took  minutes  seconds in total.