Factors and multiples

problem
Four coloured lights

Age

11 to 14

Challenge level

Imagine a machine with four coloured lights which respond to different rules. Can you find the smallest possible number which will make all four colours light up?
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
What numbers can we make now?

Age

11 to 14

Challenge level

Imagine we have four bags containing numbers from a sequence. What numbers can we make now?
problem
Differences

Age

11 to 14

Challenge level

Can you guarantee that, for any three numbers you choose, the product of their differences will always be an even number?
problem
Two much

Age

11 to 14

Challenge level

Explain why the arithmetic sequence 1, 14, 27, 40, ... contains many terms of the form 222...2 where only the digit 2 appears.
problem
Mathematical swimmer

Age

11 to 14

Challenge level

Can you work out how many lengths I swim each day?
problem
Cuboids

Age

11 to 14

Challenge level

Can you find a cuboid that has a surface area of exactly 100 square units. Is there more than one? Can you find them all?
list
Factors and multiples - secondary resources

Age

11 to 16

Challenge level

A collection of resources to support work on Factors and Multiples at Secondary level.
problem
Charlie's delightful machine

Age

11 to 16

Challenge level

Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?
problem
Transposition cipher

Age

11 to 16

Challenge level

Can you work out what size grid you need to read our secret message?