Madison finished 4/5 of her homework before dinner. What percent of Madison's homework is left to finish

20 percent.

Step-by-step explanation:

A percent is just a fraction in form x/100. This means we have to convert the denominator of the original fraction do 100. Multiply both parts of the fraction by 20, and you get 80/100. Since 80 percent has been completed, there is 20 percent left to do.