New News Maths #5

Use Prime Factor Trees To Find Prime Factors

Try writing a number as a product of its prime factors:

Example: 2*2*3=12 (2 & 3 are prime factors of 12)

Example: Write ‘220’ as a product of its prime factors (tip: use a factor tree)

Start by writing down the number ‘220’

Branch I: 110 & 2 (2 is a prime number, so circle it and leave it there)

Branch II: 10 & 11 (11 is a prime number, so circle it and leave it there)

Branch III: 2 & 5 (2 & 5 are both prime numbers, so circle them)

When there are nothing but prime numbers at the bottom of the tree, stop (it doesn’t matter how a number is factorized)

The numbers we circled earlier are prime factors of ‘220’

To write ‘220’ as a product of its prime factors we just multiply together all the numbers we previously circled.