Multiplying Time
Multiplying time is a fast way to add the same amount many times. To find how long several equal parts take, we multiply the time by how many parts there are.
Key idea
Multiply the number of minutes (or hours) by the whole number. If the minutes reach 60 or more, change every 60 minutes into 1 hour.
Turning Minutes into Hours
After multiplying, big numbers of minutes are easier to read as hours and minutes. To do this, see how many full 60s fit into the minutes. Each 60 minutes becomes 1 hour, and whatever is left over stays as minutes. This makes the answer clear and easy to say out loud.
Worked example
How long do 5 activities of 20 minutes take? 5 × 20 = 100 minutes. Since 100 = 60 + 40, that is 1 hour 40 minutes.
Remember
- Multiplying is repeated adding.
- 60 minutes = 1 hour.
- Change large minutes into hours and minutes.