Challenge Level

On the planet Vuv there are two sorts of creatures. The Zios have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zios and how many Zepts were there?

Challenge Level

48 is called an abundant number because it is less than the sum of its factors (without itself). Can you find some more abundant numbers?

Challenge Level

Find at least one way to put in some operation signs (+ - x Ã·) to make these digits come to 100.

Challenge Level

Use 4 four times with simple operations so that you get the answer 12. Can you make 15, 16 and 17 too?

Challenge Level

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

Challenge Level

Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?

This article explores the use of the array to support children's thinking around multiplication and division.