# Greatest Common Factor and Simplest Form

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```					Fractions
Greatest Common Factor & Simplest Form By Rosi Barron

<--- To Teacher Page

•Fifth grade Fractions: GCF & Simplest Form

•Tips:
-Teachers, please read through the whole presentation prior to the activity. -Each activity is meant to be used in addition to your classroom teaching. -Each activity includes a journal component.

•OBJECTIVES: TSW identify factors & use models to represent fractions in simplest from.

GCF (Greatest Common Factor) is the largest factor that can be divided into both the numerator & the denominator. A fraction is in SIMPLEST FORM when the GCF of the numerator and denominator is the number 1. Follow these steps: Step 1: Find the GCF of 8 and 12.
Factors of 8 - 1, 2, 4, 8

Step 2: Divide the numerator & denominator by the GCF.
8 ÷ 4 = 2

Factors of 12 - 1, 2, 3, 4, 6, 12 The GCF is 4 -----------

12 ÷ 4

3

The GCF of 2 & 3 is 1.

Put these steps in your journal.

Find the GCF for each of these fractions and then express them in SIMPLEST FORM.

Use the 2-step process & don’t forget to think!!!

12 15

16 32

30 40

18 45

Do this in your journal --->

Find the Greatest Common Factor. 12: 1, 2, 3, 4, 6, 12 15: 1, 3, 5, 15 16: 1, 2, 4, 8, 16
32: 1, 2, 4, 8, 16, 32

GCF: 3 GCF: 16 GCF: 10

30: 1, 2, 3, 5, 6, 10, 15, 30 40: 1, 2, 4, 5, 8, 10, 20, 40 18: 1, 2, 3, 6, 9, 18
45: 1, 3, 5, 9, 15, 45

GCF: 9

Place these in your journal. Go to step 2------------------->

Divide the numerator & denominator by the GCF.
12 ÷ 3 = 4

Simplest Form

4

15 ÷ 3 = 5
16 ÷ 16 = 1

5 Simplest Form
1

32 ÷ 16 = 2 30 ÷ 10 = 3 40 ÷ 10 = 4
18 ÷ 9 = 2 45 ÷ 9 = 5 Simplest Form

2 Simplest Form 3 4
2 5

12 = 4 15 = 5

16 = 1 32 = 2 30 = 3 40 = 4 18 = 2 45 = 5