Converting units of time

Some of the units we use to measure time are hours, minutes and seconds.  In Converting between hours, minutes and seconds, we saw how to convert between different units of time.

 We can use multiplication and division to convert between different units of time.  

Example 1

If it took $9$9 hours and $15$15 minutes to drive to Sydney, how many minutes did it take?  

Think: Firstly calculate how many minutes are in $9$9 hours.  

We know that $1$1 hour  = $60$60 minutes, so to calculate the number of minutes in 9 hours we need to multiply

$9$9 x $60$60 = $9$9 x $6$6 tens = $54$54 tens = $540$540 minutes

So there are $540$540 minutes in $9$9 hours.

Next we need to add $540$540 minutes and $15$15 minutes

Do: Calculate $540$540 + $15$15 

One way to make this calculation easier is to think of $15$15 = $10$10 + $5$5

Adding $540$540 + $10$10 + $5$5 = $555$555

So it took $555$555 minutes to drive to Sydney.

Worked Examples

Question 1

Question 2

QUESTION 3

We work with time in almost every area of our life, so knowing how to add time, calculate the time between events, or even use a 24 hour clock are important.   Let's look at some common ways we may need to work with time.  

Solving different types of time problems

In the first video, you'll see how to calculate elapsed time, how to add two blocks of time together, as well as how to work out how long you might need to binge-watch your favourite tv show!

THE 24 HOUR CLOCK

Sometimes you may need to know how to use 24 hour time, so this video shows you how to do that. It's only a short video, showing you how you can add or subtract 12, to move between the 12 and 24 hour clock.

Worked Examples

Question 1

Question 2

Question 3