A percentage is subtracted from a number by calculating the percentage in relation to that number and then performing a basic subtraction function. For example, to calculate 200 minus 70 percent, a person must first know that 70 percent of 200 is 140. Then, 140 is subtracted from 200 to get the answer, which is 60.
Before performing the subtraction step, individuals must convert the percentage to a relevant number. First, a person moves the decimal point to the left two places, converting the percentage figure to a number. Thus, 70 percent becomes 0.70. The original number is then multiplied by the percent number: In the example, 200 times 0.70 equals 140.