Factor Rainbows
“I can find all the factors
of a whole number.”
What is a factor?
Factoring means to take a number apart. Factors are what
you multiply together to get a number.
Example:
If our number is 10, two factors are 2 and 5 because 2 x 5 is
10.
What are Factor Pairs?
Factor pairs are two numbers that when
Multiplied together equal your target
number.
For example: Factor pairs for 10 are...
1 x 10 and
2x5
There are 2 factor pairs for the number ten.
Finding Factors
In order to find all of the factors of a number you need to go
through all of the numbers that can be multiplied together to
make that number.
Our example number 10 has 4 factors...
1, 2, 5 and 10 because...
1 x 10 = 10
2 x 5 = 10
It has 4 factors!
Factor Rainbows
What is a factor rainbow? A factor rainbow helps you find all
of the factors. It is called a rainbow because all of the factor
pairs connect to make a rainbow!
How do we do it!?!?!?
Making a factor rainbow is easy as pie!
Let’s try one:
Find all of the factors for the number 12.
We start by counting and seeing if a
number can be multiplied to equal 12.
How many factor pairs are there for
the number 12?
1
2
3
4
6
12
3
Steps:
Step One: Start with 1 and the number itself.
Step Two: Count up by ones to see if you can multiply two numbers
together to get your target number.
Step Three: Stop when you can’t get anymore numbers in between.
Step Four: Connect the factor pairs!
One more time...
How many factor pairs are there for
the number 18?
How many factor pairs are there for 18?
3
1
2
3
6
9
18
YOU TRY!
Make factor rainbows for the following
numbers and tell how many factor pairs
each number has.
15
24
20
63
35
17