Working with time and time zones · Usually met around P6
Hours, minutes and seconds
To a smaller unit × 60, to a bigger ÷ 60.
How to do it
Method
To a smaller unit × 60, to a bigger ÷ 60
1.5 hours = 1.5 × 60 = 90 minutes
Another way
Think in fractions
15 minutes = 1560 = 14 hour
In full
1 hour = 60 minutes and 1 minute = 60 seconds. A big unit into a small one is × 60: 1.5 hours = 1.5 × 60 = 90 minutes; 34 minute = 34 × 60 = 45 seconds. A small unit into a big one is ÷ 60: 90 minutes = 90 ÷ 60 = 1.5 hours; 18 seconds = 18 ÷ 60 = 0.3 minute. Careful: time doesn't go in tens — 1.2 hours is not 1 hour 20 minutes but 1 hour (0.2 × 60 =) 12 minutes. Another way is to think in fractions: 15 minutes is 1560 = 14 hour = 0.25 hour; 30 minutes is half an hour, 0.5 hour.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
0.75 hours = □ minutes
Show the answer and working
Answer: 45
Into a smaller unit, × 60: 0.75 × 60 = 45.
Example 2
174 minutes = □ hours (as a decimal)
Show the answer and working
Answer: 2.9
Into a bigger unit, ÷ 60: 174 ÷ 60 = 2.9.
Example 3
How long is 5.5 hours?
- A. 550 min
- B. 5 h 50 min
- C. 5 h 5 min
- D. 5 h 30 min
Choose the right answer
Show the answer and working
Answer: D. 5 h 30 min
0.5 × 60 = 30: 5.5 hours = 5 h 30 min.
Practise it in the game →Working with time and time zones · Free to start, unlimited questions, no download