Real-life hook

You buy a snack for $13 and pay with a $20 note. How much change should you get back? You can work it out in your head.

See it

20 + 13 = 33

The idea

Change is the money you get back: the amount you paid minus the cost. The easiest way is to count up from the cost to the amount you paid. From $13: 14, 15, 16, 17, 18, 19, 20 — that's $7.

Worked examples

$20 − $13 = 7

Count up from 13 to 20.
13 → 20 is 7. Change is $7.

$10 − $6 = 4

Count up from 6 to 10.
6 → 10 is 4. Change is $4.

Common mistake

Watch out: Subtracting the wrong way round — doing cost minus cash, like $13 − $20.

Better: Change = amount paid − cost. You paid more than the item cost, so start from the cost and count up to the cash.

Use it in real life

At a market stall you pay with a $5 note for a $2 item — your change is $3.

Where you'll use this

Paying with cash and checking your change
Market and cash-only stalls
Checking a receipt is right

Frequently asked questions

How do I calculate change?

Subtract the cost from the amount you paid. For a $13 item paid with $20, the change is $20 − $13 = $7.

What is the easiest way to work out change?

Count up from the cost to the amount you handed over. From $13 up to $20 is $7, so that's your change.

Calculate change