How do you find the percentage of something?
To find the percentage, you need to know the number of the part and the number of the whole. If you know only the separate numbers, you will have to add them to get the whole.
Example: In the school cafeteria, 7 students from your class chose pizza, 9 chose hamburgers, and 4 chose tacos. To find any percentage, you first add 7 + 9 + 4 = 20. The percentages can be found by dividing 7, 9, and 4 each by the whole (20). Four out of 20 students chose tacos, and 4/20 = 1/5. Changing 1/5 to a percentage tells us that 20% of the students chose tacos.