The Real Cost

When you save to make a big purchase, be sure to consider the sales tax you will have to pay.

Have you ever paid sales tax?

Lesson Objective

Find the best buy based on unit price.

Content Vocabulary

comparison shopping comparison pricing

Comparing prices to find the best value.

comparison pricing

Comparing prices to find the best value.

Oatmeal is sold in three sizes. The price of an 18-ounce package is $1.86. The price of a 42-ounce package is $3.17. The price of a 112-ounce package is $6.29.

Based on price alone, which package is the best buy?

Example 1Example 1

Find the unit price for each item.

Price per Item ÷ Measure or Count

18-ounce package: $1.86 ÷ 18 = $0.10333

$0.10333 × 100 = 10.33¢ per ounce

Example 1 Answer: Example 1 Answer: Step 1Step 1

42-ounce package: $3.17 ÷ 42 = $0.07547

$0.07547 × 100 = 7.55¢ per ounce

112-ounce package: $6.29 ÷ 112 = $0.05616

$0.05616 × 100 = 5.62¢ per ounce

Example 1 Answer: Example 1 Answer: Step 1 (cont.)Step 1 (cont.)

Find the best buy.

Compare: 10.33¢, 7.55¢, and 5.62¢ per ounce

The 112 ounce package at 5.62¢ per ounce is the best buy.

Example 1 Answer: Example 1 Answer: Step 2Step 2

Bounce fabric softener sheets are sold in an 80-count box for $3.17, a 120-count box for $4.44, and a 160-count box for $6.24.

What is the unit price for each?

Which is the best buy?

Practice 1Practice 1

$3.17 ÷ 80 = $0.039625 = 3.96¢ per sheet$4.44 ÷ 120 = $0.037 = 3.7¢ per sheet$6.24 ÷ 160 = $0.039 = 3.9¢ per sheet

The 120-count size is the best buy.

Practice 1 AnswerPractice 1 Answer