To subtract a percentage, one starts by converting the percentage into its decimal equivalent and subtracting the result from one. Multiplying the answer by the original figure gives the value after subtracting the percentage. For instance, to subtract a tax of 27 percent from base pay, one coverts the percentage to 0.27 or (27/100). Basic pay x (1 - 0.27) gives the pay after the tax deduction.
Alternatively, an employee may first calculate the actual tax (basic pay x 27/100) and then subtract it from the basic pay. If a buyer pays $7.61 for an item that was priced at $6.95, the applicable percentage sales tax (x) is calculated as follows: x = (7.61- 6.95)/ 6.95; x = 9.5 percent.
Mathematically, a percentage of any value means the value multiplied by the percentage in its decimal form. For example, 35 percent of 80 means 0.35 x 80. It’s also possible to calculate a percentage rate of a value if the actual fraction is known. For example, if x represents a percent of 20 that equals 30, the percent is calculated as follows: x = 100 x 30/20. One multiplies the rate by 100 to convert from the decimal to percentage form.