Factors and multiples

problem
Alison's quilt

Age

11 to 14

Challenge level

Nine squares are fitted together to form a rectangle. Can you find its dimensions?
problem
Number families

Age

11 to 14

Challenge level

How many different number families can you find?
problem
Give me four clues

Age

7 to 11

Challenge level

There are eight clues to help you find the mystery number on the grid. Four of them are helpful but the other four aren't! Can you sort out the clues and find the number?
problem
Which is quicker?

Age

7 to 11

Challenge level

Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
problem
What numbers can we make?

Age

11 to 14

Challenge level

Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?
problem
Missing multipliers

Age

7 to 14

Challenge level

What is the smallest number of answers you need to reveal in order to work out the missing headers?
problem
Curious number

Age

7 to 11

Challenge level

Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?
problem
Ip dip

Age

5 to 11

Challenge level

"Ip dip sky blue! Who's 'it'? It's you!" Where would you position yourself so that you are 'it' if there are two players? Three players ...?
problem
Rolling along the trail

Age

11 to 14

Challenge level

What could be the scores from five throws of this dice?
problem
Indivisible

Age

14 to 16

Challenge level

Each time a class lines up in different sized groups, a different number of people are left over. How large can the class be?