In the video, we solved problems using the part and the whole to find the percent and using the percent and the part to find the whole. We can also solve problems in which we’re given the percent and the whole and we find the part. This is also called finding the percent of a number. For example: Jamie baked 200 cookies for the bake sale, but he ate 25% of them. How many cookies did Jamie eat?
We need to find 25% of 200, and there are many ways to solve this kind of problem. We can also set up equivalent fractions, setting 25⁄100 = ?⁄200. The wording “percent of” also indicates that we can use multiplication. We can convert 25% to a fraction or a decimal and multiply it by 200 to find the part.
Juana baked 150 cookies for the bake sale and ate 10% of them. How many cookies did Juana eat?
A
15
B
10
C
100
D
30
To find the number of cookies Juana ate, we need to find 10% of 150.
To do this, we can multiply 0.10 (the decimal form of 10%) by 150:
0.10 * 150 = 15
Therefore, Juana ate 15 cookies.
The answer is A. 15.