A percent is a way of a expressing a part out of 100. Remember learning about ratios and how they compare quantities? A part-to-whole ratio is a ratio that compares a part of a whole to another part of a whole. A percent is a part-to-whole ratio where the whole is 100. 40%, or 40 out of 100, is a ratio that compares 40, the part, to 100, the whole.

Which of these could you express as a percent?

A
how many of the 100 yogurts in the refrigerator are strawberry

B
the average size of the 100 yogurts in the refrigerator

C
the maximum number of yogurts the refrigerator can hold

D
how many grams of sugar the 100 yogurts in the refrigerator have altogether
choose 1

The correct answer is A: how many of the 100 yogurts in the refrigerator are strawberry. This can be expressed as a percent by comparing the number of strawberry yogurts (the part) to the total number of yogurts (the whole) in the refrigerator.