Step 3 Objective

Know all the pairs of factors of any number up to 100.

Examples of what pupils should know and be able to do

Probing questions

Which numbers less than 100 have a large number of factors? How would you go about finding all the pairs of factors?

Do all numbers have an even number of factors? Is there anything special about those that have an odd number of factors?

How do you know when you have found all the factors for a given number?

What if pupils find this a barrier?

Give pupils practice with using the vocabulary 'factor' and 'multiple'.

Ask pupils to make some statements with 'is a factor of' and 'is a multiple of'.

Adapt and use some of the activities in Teaching mental calculation strategies to level 5 pages 33-35.