# Factors and multiples

This collection contains resources from the website 1001mathproblems.com by Sian Zelbo. The topics covered include factors, multiples, primes, and common factors. Each topic is introduced in the form of a puzzle, many of which have several different solutions. The materials are ideal for use with Key Stage 3 students.

## Resources

### Coin problem

This puzzle is about factors and multiples. A purse contains an unlimited supply of 5 cent and 8 cent coins. A candy store with 6 items will only accept exact change. The challenge is to find which items can be purchased.  There is an extension activity for making the numbers from 1 to 50 and then finding the...

### Pastry shop problem

A shop is selling cakes and cupcakes. The owner believes that \$13 is unlucky and so wants to avoid ever charging this amount. The challenge is to price the items so that the bill could come to any amount above 13. The challenge makes use of factors and multiples. This resource is suitable for Key Stage 3.

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### Factor trees puzzle

The mathematics involved in this puzzle is factorisation and this leads on to prime factors. Different factor trees for 40 are given and the challenge is to find the different factorisations. This is helpful for convincing students that there are several ways to find the prime factorisation. This resource is...

### Hex-a-puzzle 2

This puzzle is about factors and common factors. There are three puzzles to solve using a grid of 9 hexagons. The first two puzzles consider multiples. The final puzzle considers common factors and requires the numbers from 1 to 9 to be placed onto the grid so that no two adjacent numbers share a common factor...