# Factors, Multiples and Primes

This  collection of resources supports the teaching of factors, multiples and primes in secondary mathematics.

Here are some favourite activities selected by the NRICH team.

• Factors and Multiples Game A game in which players take it in turns to choose a number. Can you block your opponent?
• Factors and Multiples Puzzle Using your knowledge of the properties of numbers, can you fill all the squares on the board?
• Gabriel’s Problem Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?
• Dozens Do you know a quick way to check if a number is a multiple of two? How about three, four or six?
• Stars Can you find a relationship between the number of dots on the circle and the number of steps that will ensure that all points are hit?
• Take 3 From 5 Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can they stop him?
• Counting Factors Is there an efficient way to work out how many factors a large number has?

These are just a few of the activities on Factors, Multiples and Primes  that you can find on the NRICH curriculum pages.

The activities below, taken from the STEM Learning website, complement the NRICH activities above.