FactorsPart 1. Factors

Part 2. Common Factors Part 3. Greatest Common Factors

PART 1.

What are Factors?

3 x 4 = 12Factor Factor Product

In a multiplication sentence, like this one, it has two factors, and a product.

Factors, are numbers we can multiply together to get a product!

Finding the Factors of a number.

To find the factors of a number, just ask yourself “what two numbers am I going to multiply together to get that number”

Find the factors of 18 What numbers multiplied by each other equal 18?

It is the easiest to start from one and go in order so you don't forget about a factor! 1x18=18 2x9=18 3x6=18 6x3=18 9x2=18 18x1=18

The factors of 18 are: 1, 2, 3, 6, 18

IMPORTANT MESSAGE: YOU CAN NEVER HAVE A FACTOR THAT IS BIGGER THAN THE ORIGINAL NUMBER!

Miss Andrefski tip: to help me find the factors, I would ask myself whose multiplication facts am I going to find that number, that is a

factor of that number!

Try this one on your own…

Find the Factors of 24

You can check your work with a multiplication chart!

The Factors of 241x24=24 (24 is found in the 1’s times table) 2x12=24 (24 is found in the 2’s times table) 3x8=24 (24 is found in the 3’s times table) 4x6=24 (24 is found in the 4’s times table) 6x4=24 (24 is found in the 6’s times table) 8x3=24 (24 is found in the 8’s times table)

12x2=24 (24 is found in the 12’s times table)

LET’S CHECK YOUR WORK…

The factors of 24 are: 1, 2, 3, 4, 6, 8, 12

You can check your work with a multiplication chart!

PART 2.WHAT

Common FactorsCommon Factors- numbers that are factors of two or more products.

When two or more numbers share those factors, they are called the common factors…take a look!

Finding the common factors of 18 & 24.

First step: find the factors of the first number (18). 1x18=18 2x9=18 3x6=18 6x3=18 9x2=18 18x1=18

The factors of 18 are: 1, 2, 3, 6, 18

Second step: find the factors of the second number (24). 1x24=24 2x12=24 3x8=24 4x6=24 6x4=24 8x3=24

12x2=24 The factors of 24 are: 1, 2, 3, 4, 6, 8, & 12

Third step: Find what factors they have in common with each other.

!The factors of 18 are: 1, 2, 3, 6, 18

!The factors of 24 are: 1, 2, 3, 4, 6, 8, & 12

!

!

Common Factors = 1, 2, 3, & 6

try one on your own, remember follow the steps.

Find the common factors of 8 & 12

Follow the steps: 1.) Find the factors of the first number.

!2.) Find the factors of the second number.

!3.) Find the factors that the two numbers have in common.

Miss Andrefski tip: to help me find the factors, I would ask myself whose multiplication facts am I going to find that number, that is a factor of that number!

here is a multiplication chart to check your work!

oh yeah, the answer is on the next slide…I promise!

Common Factors of 8 & 12

Factors of 8 are: 1, 2, 4, 8

Factors of 12 are: 1, 2, 3, 4, 6, 12

Common Factors= 1, 2, & 4

How did you do??

PART 3. (the final part, don’t worry)

PART…..

Greatest Common Factor (GCF)

The GCF of two or more products is the GREATEST number that is a factor of those products.

(the BIGGEST number they have in common)

How to find the GCF: 1. Find the factors of the first number. 2. Find the factor of the second number. 3. Find the Factors they have in common with each other. 4. (final step) Find the biggest number from the common factors.

The Greatest Common Factor of 8 & 12

Factors of 8 are: 1, 2, 4, 8

Factors of 12 are: 1, 2, 3, 4, 6, 12

Common Factors= 1, 2, & 4

Greatest Common Factor= 4

4 is the GCF because it is the biggest factor that they have in common with each other.

What is the GCF of 9 & 21?

I already did the work for you, so just pick the GCF.

Factors of 9: 1, 3, 9 !

Factors of 21: 1, 3, 7, 21 !

Common Factors: 1 & 3 !

Greatest Common Factor= ______

If you said 3, then you are correct. Because 3 is

greater than 1.

Things to Remember:Factors- are numbers we can multiply together to get a product! !Common Factors- numbers that are factors of two or more products. !Greatest Common Factors- the BIGGEST factor they have in common