Operations with Rational Numbers

Adding Rational Numbers

100

9/25 + (-17/25)

What is -8/25?

200

-5/12 + 1/12

What is -1/3?

300

1/2 + -2/3

-1/6

400

-2/7 + -6/10

-62/70

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?

What is 2 cups?

Subtracting Rational Numbers

100

8/11 - 3/11

What is 5/11 ?

200

- 4/13 - 8/13

What is -12/13 ?

300

1/6 - (-6/11)

47/66

400

-1/4 - (-6/8)

4/8 or 1/2

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?

What is 15.5 inches?

Multiplying Rational Numbers

100

-5(1/3)

-5/3 

200

3/4 x -8/9

-24/36

300

-1/6 (-2/3)

What is 1/9?

400

-1/2 x -5/8

5/16

500

Travis painted for 6 and 2/3 hours. He received $27 an hour for his work. How much was Travis paid for doing this painting job?

What is $180?

Dividing Rational Numbers

100

1/4 divided by 3/8

What is 2/3?

200

3/4 divided by -5/8

-24/20

300

-15 divided by -5/8

What is 24?

400

-5/13 divided by 7/15

-75/91

500

Emma bought 3/10 yards of cording for the trim around the edge of a square pillow (4 sides). How much will she use for each side of the pillow?

3/40