Help a 6th grader out

39 = 13 * 3

702  = 234 * 3

So

[ 13 * 3 ] / [234 * 3 ]  =

[3/3] * [ 13 /234]  =

1 * (13/234)  =

13/234    =

13 / [ 13 * 18]  =

(13/13) (1/18) =

(1) * (1/18) =

1/18