7th Grade: Operations with Rational Numbers

Classify NumbersFraction/Decimal

100

-0.25

Rational Number

200

3.666666666...

Rational Number

300

PI

Irrational Number

400

18.2131415161..........

Irrational Number

500

Square root of 81

Natural, Whole ,Integer, Rational

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

-14/12

500

-1/3 + 2 5/6

15/6  or  2.5

Subtracting Rational Numbers

100

8/11 - (-3/11)

11/11 or 1

200

- 4/13 - 8/13

-12/13

300

-0.06 - (-0.86)

0.8

400

-5/12 - (-2/24)

-1/3

500

-5.5 - (-3 2/5)

-2.1 or  -2 1/10

Multiplying Rational Numbers

100

-5(1/3)

-1 and 2/3

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 divided by 3/8

2/3

200

-20 divided by 0.5

-40

300

-15 divided by -5/8

24

400

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

500

List all the properties for adding, subtracting, dividing, and multiplying positives and negatives?

-Add: Same sign? Yes: Add, keep sign OR No: Subtract, sign of biggest number. -Subtract: Keep, change, opposite and use addition rules -Multiply/Divide: Same sign: Answer is positive Different sign: Answer is negative