Vocabulary
A comparison between two numbers, using division.
Ratio
Express the following ratio in 3 ways:
Mrs. Peterson bought 4 apples and 8 oranges at the grocery store.
4 A : 8 O
4 apples to 8 oranges
4 A / 8 O
Proportional or not?
2/14 = ? = 1/8
Not proportional
Rate or not a rate?
2 : 3
Not a rate
Convert using dimensional analysis:
180 inches to feet.
15 feet
A comparison between two numbers, using division, that also has units.
Rate
Find a ratio equivalent to 15/20.
Proportional or not?
6/14 =?= 9/21
Proportional
Rate or not a rate:
60 seconds : 1 minute
Not a rate
Convert using dimensional analysis:
16 gallons to quarts.
64 quarts.
A comparison between two numbers, using division, with units, that also has a denominator of 1.
Unit Rate
Draw a picture showing a ratio of 2:5.
Answers will vary.
Solve the proportion.
x / 20 = 60 / 100
x = 12
Find the unit rate.
Tamara purchased 3 new shirts for $52.68.
$17.56 per shirt
7.5 minutes to seconds.
450 seconds
An equation stating that two ratios are equal
Proportion
Simplify the following ratio.
13:169
1:13
Solve the proportion.
5/9 = 45/y
y = 81
Find the unit rate.
Ms. Schilly ran 13 miles in 104 minutes.
8 minutes per mile
Convert using dimensional analysis.
8 kg to ounces.
(Hint: 1 kg = 2.2 lb, 1 lb = 16 oz)
281.6 ounces
Conversion from one unit system to another. Uses unit ratios as conversion factors.
Dimensional Analysis
What is the ratio of boys to girls in 7th grade today?
Reduce if possible.
1 boy : 1 girl
Solve the proportion.
16 / 196 = x / 49
x = 4
Choose the better deal.
Mr. Moloney's car can travel 52 miles on 2 gallons of gas. Mr. Selzer's car can travel 69 miles on 3 gallons of gas. Which car has better gas mileage? How do you know?
Mr. Moloney's car has better gas mileage.
Convert using dimensional analysis:
72,000 seconds to days.
10 days