# 7.04 Passing time

Lesson

## Ideas

Can you add and subtract minutes to a designated time? Try this one.

### Examples

#### Example 1

Taylan's piano lesson went from 11\text:15 until midday.

How many minutes was Taylan's lesson?

Worked Solution
Create a strategy

Midday is another word for noon. At this time both hands would be pointing at 12.

So we need to find the number of minutes between 3 on the clock and 12.

Apply the idea

The minutes hand points at 3 which means 15. When the minutes hand points at 12 it means 60 minutes.

So we need to find 60-15 by using the vertical algorithm:

\begin{aligned} &&6&0 \\ &-&1&5 \\ \hline \\ \hline \end{aligned}To subtract the 5 in the ones column we must borrow from 6: \begin{aligned} &&5\text{}^1 &0 \\ &-&1&5 \\ \hline && 4&5 \\ \hline \end{aligned}Taylan's lesson is 45 minutes.

Idea summary

The number of minutes must be between 0 and 60. If we go below this, then we are counting backwards into the previous hour. If we go over this, then we are counting forwards into the next hour.

## Passing time in minutes and hours

This video looks at calculating passing time in minutes and hours.

### Examples

#### Example 2

Find the value of: 3 hours 3 minutes + \, 3 hours 29 minutes

Worked Solution
Create a strategy

Add the minutes and hours separately.

Apply the idea

So there are 6 hours 32 minutes.

Idea summary

When adding and subtracting times, add or subtract the minutes and hours separately. Keep in mind that there are 60 minutes in 1 hour.

It can be easier to count up from one time to another, rather than try to perform a complex subtraction.

### Outcomes

#### MA2-13MG

reads and records time in one-minute intervals and converts between hours, minutes and seconds