12.5 percent is also written as 12.5% with the percent symbol, and it is understood that 100% is a whole amount of whatever you're measuring. The best way to convert 12.5% into a fraction is to write it as 12.5/100. To get rid of the decimal, simply multiply 12.5/100 by 2, since .5 * 2 is 1. Now you have 25/200.