Prime numbers

problem

Code Breaker

Age

7 to 11

Challenge level

2 out of 3

This problem is based on a code using two different prime numbers less than 10. You'll need to multiply them together and shift the alphabet forwards by the result. Can you decipher the code?
problem

Just Repeat

Age

11 to 14

Challenge level

3 out of 3

Think of any three-digit number. Repeat the digits. The 6-digit number that you end up with is divisible by 91. Is this a coincidence?
problem

What's Left?

Age

5 to 7

Challenge level

2 out of 3

Use this grid to shade the numbers in the way described. Which numbers do you have left? Do you know what they are called?
problem

Numbers as Shapes

Age

5 to 7

Challenge level

2 out of 3

Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?
problem

Swimming Pool Tiles

Age

7 to 11

Challenge level

1 out of 3

This activity creates an opportunity to explore all kinds of number-related patterns.
problem

Prompt Cards

Age

7 to 11

Challenge level

1 out of 3

These two group activities use mathematical reasoning - one is numerical, one geometric.
problem

Tom's Number

Age

7 to 11

Challenge level

1 out of 3

Work out Tom's number from the answers he gives his friend. He will only answer 'yes' or 'no'.
problem

A Conversation Piece

Age

7 to 11

Challenge level

1 out of 3

Take the number 6 469 693 230 and divide it by the first ten prime numbers and you'll find the most beautiful, most magic of all numbers. What is it?
problem

Penta Primes

Age

7 to 11

Challenge level

3 out of 3

Using all ten cards from 0 to 9, rearrange them to make five prime numbers. Can you find any other ways of doing it?
game

Factors and Multiples Game for Two

Age

7 to 14

Challenge level

1 out of 3

Factors and Multiples game for an adult and child. How can you make sure you win this game?