General Rules
(+) x (+) =
(+) or positive
-4.4 x (-6.02)
26.488
Write -0.38 as a fraction in simplest form.
-19/50
3 9/10 x (-8/3)
-10 2/5
Write 21/5 as a decimal.
4.2
(-) x (+)=
-9.4 x (-4.7)
44.18
6.4 ÷ (-3.2)
-2
-4/5 x (5/9)
-4/9
-4/11 ÷ 2/7
-1 3/11
Tell whether the expression is positive or negative without evaluating.
-3/10 x (-8/15)
positive
-7.2 x 0.1 x (-100)
72
-5.1 ÷ (-3.4)
1.5
-2 3/8 x -8/5
3 4/5
9/10 ÷ (-6/5)
-3/4
How is multiplying and dividing rational numbers similar to multiplying and dividing integers?
The same rules for signs of integers are applied to rational numbers.
A 14.5-gallon gasoline tank is 3/4 full. How many gallons will it take to fill the tank?
3 5/8 gallons
32.436 ÷ (-4.24)
-7.65
The elevation of a sunken ship is -120 feet. Your elevation is 5/8 of the ship's elevation. What is your elevation?
-75 ft
Find the next two numbers in the pattern.
-8748, 2916, -972, ...
324, -108 (dividing by (-3) each time
Tell whether the expression is positive or negative without evaluating.
-6/5 ÷ (-1/2) x -6.3 x (-0.6) ÷ -2/3 x 7 7/8 ÷ -100
positive
A rectangular prism has a length of 5/8 inch and a width of 7/9 inch. The volume of the prism is 7/8 cubic inch. Find the height of the prism.
Volume of prism = Length x width x height
How many 2.25-pound containers can you make with 24.75 pounds of almonds?
11 containers
-3/5 x (2 2/7) x (-3 3/4)
5 1/7
How many 1 1/4 pound packages can you make with 7 1/2 pounds of cashews?
6 packages