Here is a sale tag from a shop window: 30% OFF a coat priced €50.

Before we work anything out: roughly, do you pay a bit less than €50, half of €50, or nearly nothing? And what is the quickest way you can think of to find the actual price you'd pay at the till?

Each price is drawn as a long bar, and the bar is cut into parts: the slice that comes off in the sale and the slice you still hand over at the till. Look at where the discount slice lands, and how much of the price is left to pay.

The last one works the other way. There the tax called VAT is an extra slice added on the end, so the bar gets longer and the total gets bigger rather than smaller. Work out what each slice is worth in euro before the labels are shown.

Here are three more price bars, one under the other. The first is a €40 jacket with 20% off. The second is a €120 bill with 10% off. The last is a €30 net price with 23% VAT added on top.

Read each bar together. For every bar, explain how the euro amount of each part comes from the percentage.

Today we work through these together in your copy, each one a step harder:

• €60 coat, 20% off — find the sale price
• €35 game, 30% off — how much is saved?
• €120 net price, 23% VAT — find the total
• Tricky one: €80 coat, 25% off, then 23% VAT on the new price