To get 1/5 as a percentage, you multiply the denominator (5) by 20 to get 100. Then, you have to multiply the numerator (1) by 20 as well, so you get 20/100 which is 20%. As a decimal you do multiplying again, but only by 2 to get 2/10, and two tenths is equal to 0.2. Hope this helps!
