8.1.10 Which Percent is It?
You probably agree that comparing percentages can be easier than comparing fractions. When we have a certain quantity, how do we write it as a percent of another, usually larger, number?
For example, if 42 people out of a group of 70 people agree to participate in a new community project, what percentage of the group is this?
Whenever you have a part of a group and the whole of the entire group, you can calculate percent by setting up the ratio of “part over whole.” You can then turn this fraction successfully into a percentage.
So in this case, turn into a percent, first by multiplying by 100% and then by reducing by 10 and then by 7:
(Note: You also could have reduced to first and then turned it into a percent.)
These calculations show us that 60% of the group agree to participate in the community project.
As you know, the calculation can be performed even quicker with a calculator, as can the other percent calculations.
To express one number as a percentage of another, divide the first number by the second and convert the result into percent by multiplying by 100%.