Adding and Subtracting Fractions Lesson

Adding Subtracting Fractions

Adding and Subtracting Fractions Rules

1. Before you can add or subtract the denominators have to be the same.

2. While you are adding or subtracting, the numerator changes, the denominator stays the same.

Example

1/4+2/4=3/4

5/6-3/6=2/6

Multiple Choice

Kayla had 1/6 of the cake and Jim had 3/6 of the cake. How much cake did they take in total?

• 6/6

• 2/6

• 1/2

• 4/6

Multiple Choice

Kayla has 3/9 of a pizza and Lille gave her 2/9 of a pizza. How much pizza does Kayla have now?

• 5

• 5/9

• 1/9

• 6/9

Multiple Choice

Mr. Smith buys 5/8 pound of red grapes and 2/8 pound green grapes. How many pounds did Mr. Smith buy?

• 7/8 pound
• 3/8 pound

Multiple Choice

Mickie ate 1/5 of her candy bar on Monday. She ate 4/5 of her candy bar on Tuesday. How much more of the candy bar did she eat on Tuesday than Monday?

• 5/5

• 3/5

• 1/5

Multiple Choice

• 5/14

• 3/7

• 5/7

• 5/14

Multiple Choice

• 5/14

• 3/7

• 5/7

• 5/14

Multiple Choice

Jim ran 9/10 oif a mile. Katie ran 4/10 of a mile. How much farther did Jim run than Katie?

• 13/10

• 5/10

• 1/10

• 6/10

Decompose

This is when a fraction is broken down

Decompose to Unit Fractions

Is when a fraction is decomposed to its unit.

Example

3/4=1/4+1/4+1/4

Remember the numerators are 1.

Multiple Choice

Which of the following is NOT a unit fraction?

• 1/2

• 3/4

• 1/9

• 1/4

Multiple Choice

Which of the following is a unit fraction?

• 2/5

• 5/8

• 1/8

• 7/10

Multiple Choice

Decompose 5/12 into the sum of its unit fractions.

• 1/5+1/5+1/5+1/5+1/5 = 5/12
• 1/12+1/12+1/12+1/12+1/12 = 5/12
• 1/5+1/12+1/5+1/12+1/5 = 5/12
• 4/12+1/12 = 5/12

Multiple Choice

A unit fraction has _____ as its numerator.

• 1
• 2
• 3
• 4

Multiple Choice

Decompose the following fraction:
6/10

• 1/6 + 5/6
• 2/10 + 4/10
• 3/10 + 2/10
• 1/10 + 1/10 + 3/10

Multiple Choice

How can you get 3/4?

• 1/4 + 1/4

• 2/4 + 1/4

• 1/4 + 1/4 + 1/4 + 1/4

• 3/4 + 1/4