7th Grade: Operations with Rational Numbers

Order of Operations

100

2 + 7 x (-3³) 

-187

200

8 ÷ 4 x 1/4

0.5

300

2² - 5 x 5

-21

400

(4 x 1/2) ÷  12

1/6 or 0.17

500

(1/2-2/5) x (-2³)

-4/5

Adding Rational Numbers

100

3.15 + 2.25

5.40

200

0.38 + (-1.2)

-0.82

300

9/25 + (-17/25)

-8/25

400

-5/4 + 1/12

-1 1/6

500

To make a small amount of play dough, you can mix 1 cup of flour, 1/2 cup of salt and 1/2 cup of water. What is the total amount of ingredients added to make the play dough?

2 cups

Subtracting Rational Numbers

100

8/11 - 3/11

5/11

200

- 4/13 - 8/13

-12/13

300

-0.06 - (-0.86)

0.8

400

-5/12 - (-2/24)

-1/3

500

The snowfall in Rochester, NY in the winter of 1999-2000 was 91.5 inches. Normal snowfall is about 76 inches per winter. How much more snow fell in the winter of 1999-2000 than is normal?

15.5 inches

Multiplying Rational Numbers

100

2.34¹

2.34

200

-3.2 x 5

-16

300

-1/6 (-2/3)

1/9

400

-2.57 (-.5)

1.285

500

Joe had a breakfast party. He invited four of his best friends. Each friend brought 3.4 cups of coffee. How much coffee did they all bring together?

13.6 cups

Dividing Rational Numbers

100

1/4 ÷ 3/8

2/3

200

-20 ÷ 0.5

-40

300

-15 ÷ -5/8

24

400

-5 ÷ 1/5

-25

500

Emma bought 2 and 1/2 yards of ribbon to make bows for 4 of her friends. How much yard will she use for each ribbon?

5/8 yards