Middle School Math Huddle
Fractions Review & Summary
Factors and Multiples
1∙12
2∙6
3∙4
The key to fractions is understanding factors and multiples.
12______
12
24
36
______18______
1∙18
18
2∙9
36
3∙6
54
The GCF of 12 and 18 is 6
The LCM of 12 and 18 is 36
The Greatest Common Factor (GCF) of two number
is the largest number that is a factor of both.
The Least Common Multiple (LCM) of two numbers
is the smallest number that is a multiple of both
Simplifying Fractions
To simplify a fraction, find the GCF of the numerator and denominator and factor it out.
Then cancel the common factor.
𝟏𝟐
𝟏𝟖
=
𝟔∙𝟐
𝟔∙𝟑
=
𝟐
𝟏𝟓
𝟑
𝟐𝟏
=
𝟑∙𝟓
𝟓
=
𝟑∙𝟕
𝟕
Adding and Subtracting Fraction
To add or subtract fractions, find the LCM of the two denominators. Then multiply each fraction so that the
LCM is the denominator of both.
𝟑
𝟏𝟐
𝟑
∙
𝟑
𝟑 𝟏𝟐
𝟗
𝟑𝟔
+
+
+
𝟒
𝟏
𝟏𝟖
𝟒
𝟒
𝟏
−
𝟔
𝟐
𝟑 𝟏
𝟏 𝟐
𝟏𝟖 𝟐
𝟑 𝟒
𝟔 𝟐
∙
∙ − ∙
𝟖
𝟑
𝟑𝟔
𝟏𝟐
−
𝟏𝟕
𝟏
𝟑𝟔
𝟏𝟐
𝟐
𝟏𝟐
Multiplying and Dividing Fractions
To multiply fractions, multiply the numerators and denominators. Simplify if possible.
𝟐 𝟑
𝟔
𝟑 𝟒
𝟏𝟐
∙ =
=
𝟏
𝟒 𝟐
𝟖
𝟐
𝟕 𝟑
𝟐𝟏
∙ =
To divide fractions, invert (flip) the second fraction and multiply.
𝟑
𝟖
𝟐
𝟑 𝟓
𝟏𝟓
𝟓
𝟖 𝟐
𝟏𝟔
÷ = ∙ =
Middle School Math Huddle
Fraction Review
Practice Pages
Instructions:
1) Prepare a solution page by writing “Fraction Review” and your name at the top
of the page.
2) For each problem:
a) Number a space on your solution page and neatly copy the problem.
b) Solve the problem on your White Board, showing all of the steps.
c) Neatly copy your solution onto the solution page.
d) Leave plenty of space for each problem and use extra pages as needed.
Find the Least Common Multiple (LCM)
1) 10 12
2) 12
24
4) 7 8
5) 10 25
3) 4 11
6) 8 9
Simplify (be sure to show GCF and cancellation)
7)
10)
𝟔
8)
𝟖
𝟏𝟒
𝟒𝟐
𝟏𝟓
𝟗
9)
𝟏𝟖
11)
𝟏𝟎
14)
𝟏
𝟐𝟕
𝟏𝟐
12)
𝟓𝟎
𝟖
Find the sum or difference:
13)
𝟏
16)
𝟒
𝟑
𝟗
+
−
𝟐
𝟓
𝟏
𝟔
17)
𝟐
−
𝟓
𝟏𝟐
𝟏
𝟑
+
𝟓
𝟏𝟎
15)
𝟑
18)
𝟒
21)
𝟑 𝟏
𝟒
𝟗
+
−
Find the product or quotient:
19)
𝟒 𝟑
∙
𝟗 𝟓
20)
𝟓
𝟖
÷
𝟑
𝟒
∙
𝟕 𝟐
𝟏
𝟖
𝟏
𝟔