7th Grade Math

Find a Unit Rate

JUICE Find the unit price if

it costs $2 for eight juice

boxes. Round to the nearest

cent if necessary.

$2 for eight boxes = _$2

8 boxes

Write the rate as a fraction.

= _$2 ÷^8

8 boxes ÷ 8

Divide the numerator and thedenominator by 8.

= _$0.25

1 box

Simplify.

The unit price is $0.25 per juice box.

c. ESTIMATION Find the unit price if a 4-pack of mixed fruit sells

for $2.12.

Compare Using Unit Rates

DOG FOOD The prices of 3 different bags of

dog food are given in the table. Which size

bag has the lowest price per pound?

• 40-pound bag

Dog Food Prices

Bag Size (lb) Price ($)

40 49.00

20 23.44

$49.00 ÷ 40 pounds = $1.225 per pound 8 9.88

• 20-pound bag
  $23.44 ÷ 20 pounds = $1.172 per pound


• 8-pound bag
  $9.88 ÷ 8 pounds = $1.235 per pound
  At $1.172 per pound, the 20-pound bag sells for the lowest price
  per pound.

d. FOOD Tito wants to buy some Peanut Butter Sales

Brand Sale Price

Nutty 12 ounces for $2.19

Grandma’s 18 ounces for $2.79

Bee’s 28 ounces for $4.69

Save-A-Lot 40 ounces for $6.60

peanut butter to donate to the

local food pantry. If Tito wants

to save as much money as

possible, which brand should

he buy?

Dividing by Whole

Numbers

Place the decimal point in

the quotient directly

above the decimal point

in the dividend.

0.25

8  2.00

• 16
  40


• 40
  0

Alternative MethodAlternative Method

One 40-lb bag is equivalent One 40-lb bag is equivalent

to two 20-lb bags or five to two 20-lb bags or five

8-lb bags. The cost for one 8-lb bags. The cost for one

40-lb bag is $49, the cost 40-lb bag is $49, the cost

for two 20-lb bags is about for two 20-lb bags is about

2 x $23 or $46, and the 2 x $23 or $46, and the

cost for five 8-lb bags is cost for five 8-lb bags is

about 5 x $10 or $50. So, about 5 x $10 or $50. So,

the 20-lb bag has the lowest the 20-lb bag has the lowest

price per pound.price per pound.

Lesson 1B Proportions 267

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