First you move the decimal point to the right 2 spaces to change the percent (%) to a decimal (change 45% to .45); and then you multiply by the 120. So it turns into
.45 x 120 = 54 the answer is: 54
To check you go in the opposite direction. Move the decimal point to the right ( 45 x 120 ) and the answer is 5400; which is a whole number, which means the decimal is invisibly at the end; then move the decimal point back two spaces to the left and it now looks like this 54.00; which is a whole number and the two zeros at the end can be taken off; there's that invisible decimal that makes it a whole number that you p.s. don't ever need... You are right back to 54 :)
