KS4 Foundation HCF
Before teaching Foundation HCF I teach LCM using times tables as multiples, then I introduce factors using times tables. I start with 12 and show that it is in the 2, 3, 4, 6 and 12 times tables and 2 x 6 = 12 etc.
Then I show that 1, 2, 3, 4, 6 and 12 are the factors of number 12. Then I show that 13 can only be formed from 1 x 13 and define 13 as prime.
For their activity I use the resources shown in this link to get to the highest common factor of 2 numbers.
Normally the differentiation is the main issue as some grasp this very quickly and yet others struggle, especially those that are weak on their times tables. So this list shows the resources for the extension for those who need to be kept busy and stretched.
For further differentiation I use harder numbers and then 3 numbers to solve.