What are the first five multiples of:a)3b)4c)11d)21

3, 6, 9, 12, 154, 8, 12, 16, 2011, 22, 33, 44, 5521, 42, 63, 82, 105

A multiple of a number is what you get when you multiply that number by some other whole number.

Multiples are Usually Larger Than Individual numbers, Possibly Larger never Ever Smaller

What are the factors of:a)16b)30c)8d)7

1, 2, 4, 8, 161, 2, 5, 6, 15, 301, 2, 4, 81, 7

A factor is a whole number which divides exactly into a whole number, leaving no remainder.

Factors Are Certainly Tiny Or Really Small

A prime number has exactly two factors: 1, and the number itself.

• What is the LCM of :a)4 and 5b)10 and 30 c) 12 and 15

203060

• What is the HCF of :a) 3 and 12b) 30 and 56c) 21 and 40

321

Go to Google, and type in ‘nrich factors and multiples game’ then click on ‘I’m Feeling Lucky’. Scroll down the screen until you see the interactive game and click on ‘Full Screen’.

How to play:The first player chooses a positive even number that is less than 50, and drags the number from the left hand grid and drops it on the right hand grid.The second player chooses a number to drag across. The number must be a factor or multiple of the first number.Players continue to take it in turns to choose numbers, at each stage choosing a number that is a factor or multiple of the number just chosen by the other player.The first person who is unable to take a turn loses.

QuestionsDo you have any winning strategies?Are there any numbers you shouldn't go to?

ExtensionWhen you have found some winning strategies and written them in your book, change the aim of the game:Work in pairs trying to find the longest sequence of numbers that can be selected. Each number can only appear once in a sequence.Can more than half the numbers be chosen?