# Using prime factors to find all factors

Created by
danwalker

A complete lesson on prime factors. Intended as a challenging task to come after pupils are familiar with the process of expressing a number as a product of prime factors (see my other resources for a lesson on this).

Activities included:

Starter:
Questions to test pupils can list all factors of a number using factor pairs.

Main:
Pupils find all factors of a number using a different method - by starting with the prime factor form of a number and considering how these can be combined into factor pairs. Links well to the skill of testing combinations that is in the new GCSE specification. Possible extension of pupils investigating what determines how many factors a number has.

Plenary:
A look at why numbers that are products of three different primes must have 8 factors.

No worksheets required and answers included throughout.

\$3.91
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### Info

Created: Feb 14, 2018

Updated: May 5, 2018

#### Activity

pptx, 168 KB

3-using-PPF-to-list-all-factors-of-a-number

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