Page 178 - NUMINO TG_6A

11Three Apples, Five Oranges Unit

Eggs Example: Eggs
Market B
Market A Step 1: Determine the unit rate: The students

are trying to determine how much 1 egg

2 eggs for $1 5 eggs for $2 costs, or dollars per egg.

unit rate: $1 = 1 2 = $0.5 unit rate: $2 = 2 5 = $0.4 Step 2: Set up a ratio.
2 2 2 1 5 5 5 1

= $0.5 = $0.4 Market A: Dollars = $1
Eggs 2
The price of 1 eggs is $0.1 cheaper at market B.

Milk Market B: Dollars = $2
Market B Eggs 5

Market A Step 3: Simplify the ratio as a decimal.

Market A: 2 $1 $0.5

Market B: 5 $2 $0.4

0.5 gallon for $1.20 2 gallons for $4.50 Step 4: Compare the unit rates; lower is

unit rate: $1.2 = 1.2 0.5 = $2.4 unit rate: $4.5 = 4.5 2 = $2.25 cheaper. $0.5 $0.4
0.5 0.5 0.5 1 2 2 2 1

= $2.4 = $2.25 Market B is cheaper.

The price of 1 gallon of milk is $0.15 cheaper at market B.

Market A Cherry Tomatoes
Market B

4 pounds for $5 5 pounds for $8

unit rate: $5 = 5 4 = $1.25 unit rate: $8 = 8 5 = $1.6
4 4 4 1 5 5 5 1

= $1.25 = $1.6

The price of 1 pound of cherry tomatoes is $0.35 cheaper at market A.

11. Three Apples, Five Oranges 99

Which Market Should I Pick?

Before picking a market, try to calculate the unit rate for each market quickly using mental math.

Example: Eggs.

2 eggs for $1

Always divide the first number by the second number. 1
2

It is easy to see that this is 0.5.

5 eggs for $2

Divide the first number by the second number. 2
5

Use mental math to find 2 0.4 6A Unit 11 161
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