Imagine you have exactly €5 to spend at the class tuck shop. A lunch roll costs €3.50, a drink costs €1.50, and a bag of fruit costs €0.90. Could you buy all three? Which two would you pick if you wanted a treat and some money left over?

Here are three receipts from the tuck shop. Each time we have €5 to spend. On each receipt, the prices of the things bought are added to make the total at the bottom.

1. Receipt 1: how much is left from €5?
2. Receipt 2: check the total by adding the two prices. How much is left?
3. Receipt 3: can we pay for this with €5? By how much is it over?

Let's build shopping lists together, staying at or under €5. Here are the tuck-shop prices:

• Drink €1.50
• Snack bar €2.20
• Fruit €0.90
• Biscuits €0.80
• Lunch roll €3.50

We will work through these one at a time:

1. Drink and fruit. Does it fit?
2. Snack bar and biscuits. How much is left?
3. Drink and snack bar. How much is left?
4. Add a snack bar to the drink and fruit list. Predict whether it stays under €5 before we check.

Four shopping puzzles, each with €5 at the tuck shop. Work each one out first, in your head or on paper. Then fill the basket and press Check.

1. Buy a snack bar and one more item so you get exactly €1.30 change.
2. Spend exactly €5 on two items.
3. Buy three different items that cost exactly €4.60.
4. Buy a drink, a snack and a piece of fruit for as little as you can. Biscuits and the snack bar are both snacks.