The model represents

Question

3
÷
1
5
.
Which multiplication can you use to check the answer?

Three squares are shown. Each square is divided into 5 fifths.

A.
3
×
1
5
=
3
5
B.
15
×
1
5
=
3
C.
15
×
3
5
=
9
D.
15
×
5
3
=
25

Answer 1

The correct multiplication you can use to check the answer is:

15 x 3/5 = 9

This is because division can be checked by multiplying the numerator (top number) by the reciprocal of the denominator (bottom number). So in this case, 3/5 is the reciprocal of 5/3, which is what we would get if we flipped the fraction. Then, multiplying 15 by 3/5 gives us 9, which matches the original division of 3/15.