Question

Melanie’s bedroom walls are 45% painted. The area of her walls totals 420 square feet. What is the number of square feet of Melanie’s walls that still need to be painted?

Answer 1

She still needs to paint 231 square feet.
You can get that by find out what 45% of 420 is (420 x 45 = y, divide it by 100), and subtracting it from 420 (420 - 189 = 231).
Or you can go right ahead and calculate what is the remaining percentage, which is 55%, so (420 x 55 = y, divide it by 100).

Answer 2

The answer is 231 square feet. 45% is .45 in decimal form. You would multiply .45 by 420 and get 189. Then you would subtract 189 from 420 and get 231.