Question

1student used a calculator to divide a number by , when instead the student meant to multiply the3umber by 9. Which of the following single arithmetic operations can be performed to produce thetended result?1A. Multiply by91OB. Multiply by3O C. Multiply by 3O D. Divide by 3* O E. Divide by 9

Answer 1

- The student ought to multiply the number by 3 (option C ) in order to obtain the intended result, for the following reasons:

a) By initially dividing the number by 1/3, the student is actually multiplying the number by 3 (because the reciprocal of 1/3 is what the number will be mutiplied by)

b) Since the student had multiplied the number by 3, as explained in (a) above, the student will have to multiply the number by 3 again so that, in all, the student will have achieved the initial goal of multiplying the number by 9, since 3 * 3 * number = 9 * number.