Description: Let's think about what percent really means by looking at a 10 by 10 grid. Created by Sal Khan and Monterey Institute for Technology and Education. 20% is equal to 20 percent, which literally means 20 per cent. If you want to shade 20%, that means, if you break up the square into 100 pieces, we want to shade 20 of them. So if we go horizontally right here, we have one, two, three, four, five, six, seven, eight, nine, ten squares.*Teacher Advisor is 100% free.