what is 21% in a fraction

21%   

Remember that  "percent"....means "per hundred"....so we have "21 per 100"  =

21  / 100

I used to think that the percent sign (%) was made of a "1" and two ''0"s, which can be formed into 100. So a percent (%) of something is something out of 100. 

21% = $\dfrac{21}{100}.$