Ratios and Rates

1
Ratios and Rates
2
Ratios and Rates
ratio a comparison of two numbers by division
written in several different forms.
3
Ratios and Rates
rate a ratio that compares different kinds of
units by division to obtain a unit rate or rate
per unit.
4
Ratios and Rates
The order of the numbers in a ratio should match
the order of the words in a ratio.
apples to oranges
2 to 3
5
Ratios and Rates
Ratios can be written in several different ways.
red to white
3 to 1
3 1
3/1
6
Ratios and Rates
Ratios can show comparisons between
part to part
red to green 1 to 2
green to red 2 to 1
7
Ratios and Rates
Ratios can show comparisons between
part to whole
red to whole 1 to 3
green to whole 2 to 3
8
Ratios and Rates
Ratios can show comparisons between
whole to part
whole to red 3 to 1
whole to green 3 to 2
9
Ratios and Rates
Compare octagon to all shapes
1 out of 8
1 8
1/8
1 to 8
10
Ratios and Rates
Compare all shapes to trapezoid
8/1
8 to 1
8 1
11
Ratios and Rates
Compare pentagons to hexagons
2/3
2 to 3
2 3
12
Ratios and Rates
Give each ratio in three forms.
8 roses out of 24 flowers
8 to 24
8 24
3 dogs out of 12 animals
3 to 12
3 12
13
Ratios and Rates
A ratio in fraction form can be expressed in
simplest form by dividing the numerator and
denominator by a common factor.
8
3


3
8
14
Ratios and Rates
To express a ratio as a rate per unit, write the
ratio as a fraction and then divide the numerator
by the denominator.
395 miles in 5 hours
miles
miles
79 miles per hour

hours
hours
15
Ratios and Rates
Express each ratio as a rate.
5 inches of rain in 30 days
5

inch of rain per day
5
120 words in 3 minutes
40 words per minute
words

per minute