To solve a problem about percent of change, you need to divide the amount of change by the original amount. To find the amount of change, subtract the initial amount from the final amount. The formula for percent of change can be written:
Percent of Change = (Final amount - Initial amount)/Initial amount
For example, If you start with 100 and end with 120, you would write:
Percent of change = (120 - 100)/100
Percent of change = 20/100
Percent of change = .2
Since you want a percent, you need to change the decimal to a percent. To do this, move the decmial place 2 places to the right and add a percent sign.
Percent of change = 20%