Skill: Compare unit prices

To compare prices fairly, find the unit price for each option. A unit price tells you the cost of one unit, such as 1 ounce or 1 item.

Example

A store sells two boxes of cereal:

• Box A: $(12)$ ounces for 4.80$
• Box B: $8$ ounces for 3.76$

Which box is the better value?

Step 1: Make sure the units match.

Both quantities are measured in ounces, so we can compare their prices per ounce.

Step 2: Find the unit price of each box.

Divide the total price by the number of ounces:

$$\text{Box A: } \frac{\$4.80}{12}=\$0.40\text{ per ounce}$$ $$\text{Box B: } \frac{\$3.76}{8}=\$0.47\text{ per ounce}$$

Step 3: Compare the unit prices.

$$\$0.40 < \$0.47$$

Box A costs less for each ounce.

Answer: Box A is the better value, even though it has the higher total price. Always compare the unit prices, not just the package prices.