Question

Mrs. Bennett has graded 20% of her 150 students' papers. How many papers does she still need to finish grading?

Answer 1

150 - (150 x 20%)
or
150 - (150 x .2)

Simplified:

150 - 30
120

Answer 2

120

You can find out how many she has graded by multiplying 150 by the decimal version of 20% (.20). Then, subtract the number you get by 150.