Add & Subtract Fractions

Barbara Shephard

Cobb 6th Grade Campus

GPISD

OBJECTIVE

The student is expected to model addition and subtraction situations involving fractions with objects, pictures, words, and numbers.

Purpose

Student will be able to:

• Understand the basic fraction concepts by solving problems using models

• Add and subtract fractions using models to help illustrate the process

Problem # 1

John has 5 ½ hours left before his school project is due. He has to work 2 ¼ hours before he can start on project . How much time does he have to work on project?

5 ½ =5 2/4     

- 2 ¼ =2 ¼

3 ¼

Problem #1

5 ½ = 5 2/4     - 2 ¼ =2 ¼

3 ¼          

Problem #2

Ms. Shorter made a cake for her son. She used a half stick of butter , 3 ½ cups of sugar, 2 ¼ cups of flour, and 6 eggs. What were the total measurement of the ingredients used to bake the cake?

½ 3 ½ 2 ½ +6 11 3/2 = 12 ½

Problem #2

½

3 ½

2 ½

+6

11 3/2 = 12 ½ (3 divided by 2 equals 1 ½ ) ( 11 plus 1 ½ equals 12 ½ )

Guided Practice

4 ½ 2 2/4 10 7/10

+ 7 3/8 +7 1/3 +15 2/15

17 2/4 42 2/4 32 2/6

- 12 ¼ - 10 3/12 - 5 1/6

Independent Practice

Go to:– www.ask.com– http://illuminations.nctm.org/tools/index.as.px

Conclusion

From observations of mathematical fraction models, students should be able to effectively solve the addition and or subtraction of fraction.