Question

A serving of Ice cream contains 6400 calories. 1600 calories come from fat. What percent of the total calories come from fat

Answer 1

Just divide.

1600 / 6400 = 0.25

0.25 * 100 = 25%

Answer 2

We know that 1600 is an unknown percent of 6400, so we can write it down as:

1600 = x% from 6400
1600 = x/100 * 6400
1600 = x * 64
1600 = 64x                      / ÷ 64 (both sides)
x = 25

Doublecheck:

6400 * 25% =
= 6400 * 25/100 =
= 6400 * 1/4 =
= 6400/4 =
= 1600, so it's correct ;)