Factors, Multiples, Primes

Factors & Multiples 

Factors are numbers you multiply together to get other numbers. 

So for instance 2 and 5 and factors of 10, because 2 x 5 = 10 

The other factors of 10 are 1 and 10, because 1 x 10 = 10

There are no other factors of 10 because no other numbers divides evenly into it. 

Some numbers have a lot of factors. For example, how many factors of 100 can you find? 

Try the Online Factor Finder

Still need help on factors?  Make sure you keep practicing your times-tables!

 Maths is Fun: Factors and Multiples (explanation)

Khan Academy: Factors and Multiples (video)

Khan Academy Finding factor pairs (practice)

Khan Academy: Identifying factors and multiples (practice)

Skills Check: Are you Ready to Learn about Prime Factorisation?

• Can you mentally work out if any number is divisible by 2,3,4,5,6,9 or 10? 
• Can you easily identify if a number under 100 is prime?
• Can you name the next four multiples of any number under 100? 
• Can you find the Lowest Common Multiple of any pair of numbers?

Prime Numbers & Prime Factorisation

Math is Fun: Factor Trees (explanation)

Khan: Prime Factorization (video)

Maths is Fun: Prime Factorisation (practice)

Khan Academy: Prime Factorisation (practice)

Extension:

How to find how many factors any number has (instructions)

Making square numbers by adding primes (activity)

Prime Magic (activity) 

Peculiar Patterns in Primes (news article)