Multiplying and Dividing Rational Numbers

General Rules

100

Will the answer be positive or negative: 

8.4 x 1/4

(+) or positive

200

Will the answer be positive or negative:

-9.75 / 0.25

negative

300

Tell whether the expression is positive or negative without evaluating.

-3/10 * (-8/15)

positive

400

How is multiplying negative decimals and fractions similar to multiplying negative integers?

The same rules for signs of integers are applied to fractions and decimals.

500

Tell whether the expression is positive or negative without evaluating.

-6/5-:(-1/2)*6.3

Positive

Multiplying Decimals

100

-4.0 x (-6.0)

24

200

-0.9 x 4

-3.6

300

-7.2 x 0.1

-0.72

400

-9.25 x 0.3

-2.775

500

-0.06 x (-0.05)

0.003

Multiplying Fractions

100

9/10 * (-2/3)

-3/5

200

-5/8 * (-4/15)

1/6

300

-2 3/8*(-1 3/5)

19/5 or 3 4/5

400

-12 * 5/8

-15/2 or -7 1/2

500

-3/5 * 2 2/7

-48/35 or -1 13/35

Dividing Decimals

100

0.35 / (-7)

-0.05

200

-12.25 / (-5)

2.45

300

72.3 / (-0.3)

-241

400

-67.56 / 1.2

-56.3

500

Nellie went to the hardware store bought 197.64 meters of yellow rope.  She planned to cut the rope into equal pieces measuring 1.2 meters How many pieces can she cut? 

164 pieces; 164.7

Dividing Fractions

100

-5/6-: 1/6

-5

200

-4/11-: -2/7

14/11 or 1 3/11

300

9/10-:(-1 1/5)

-3/4

400

-4 1/6-:1 1/3

-3 1/8 or -25/8

500

-1/8-: 6 1/10

-5/244