Liz wants to buy her favorite musical group's new CD. The CD costs $15.24, including tax. Liz gives the store clerk a twenty-dollar bill. How much change should Liz get back?*

This question can be solved quite easily. So, how much change should Liz get from a twenty-dollar bill if her favourite musical group's CD costs $15.24 including tax?

This can be broken down to find the answer easily. Once you've got the technique, you should be able to do this in your head!

The best way to do this is to round up to $20:

1. Let's round the 24c up to $1.
2. Number bonds to 10 mean that 24c + 6c = 30c. And 30c + 70c = $1.
3. So we've rounded up to $16 using 76c. The next bit is easy.
4. $16 + $4 = 20.
5. So... $4 + 76c = $4.76.

Liz should get $4.76 change!

You might find this method in this video helpful - it's in Pounds Sterling but it should still show you the same thing - this method uses a number line: