Working systematically

This multiplication uses each of the digits 0 - 9. Can you work out where each digit goes?

Can you use four digits to make four two-digit numbers that add to 100?

Can you make square numbers by adding two prime numbers together?

A 750 ml bottle of concentrated orange squash is enough to make fifteen 250 ml glasses of diluted orange drink. How much water is needed to make 10 litres of this drink?

Andy had a big bag of marbles but unfortunately the bottom of it split and all the marbles spilled out. Use the information to find out how many there were in the bag originally.

Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.

Can you see how these factor-multiple chains work? What can you find out about them?

Find the product of the numbers on the routes from A to B. Which route has the smallest product? Which the largest?

A group of children are using measuring cylinders but they lose the labels. Can you help relabel them?

Each light in this interactivity turns on according to a rule. What happens when you enter different numbers? Can you work out the rule for each light?