6th Grade Math Textbook, Progress

Rates

11-3

6 miles in 1 hour

is called a unit rate.

A rate is a ratio that compares two quantities with

different units of measure. A unit rate is a rate that has

1 unit as its second term, or denominator.

Rates are used almost every day. For example, average

speeds and prices are often given as rates.

Moya ran 18 miles at a steady pace in 3 hours.

Her average speed can be expressed as a ratio:

^1

3

8

h

m

ou

ile

rs

s

18 miles : 3 hours 18 miles in 3 hours

To find how many miles Moya ran in 1 hour, x,

use equivalent ratios.

1

3

8

h

m

ou

ile

rs

s





x

1

m

ho

ile

u

s

r


 


1

. 3

8

.



3

3





6

1

Moya ran 6 miles in 1 hour, or 6 miles per hour.

Four ballpoint pens cost $2.20.

This rate of cost can be given as a ratio.

^4

$2

p

.

e

2

n

0


s 4 pens : $2.20 4 pens for $2.20

To find the cost of one pen, p, use equivalent ratios.



^4

$2

p

.

e

2

n

0


s  
^0

$

.

2

4

.2

..

0

0





4


^4 


$.

1

55

One pen costs $.55.

1 pen

p

1 unit

price of 1 unit

total number of units

total price

A unit price is the

cost of one item.

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