Reconstructing division problems is kind of like detective work only instead of reconstructing a crime scene we're reconstructing the division problem. Our clues are the quotient (the answer) and the divisor (the number we divide by). We have solved our problem when we find the dividend (the number which is divided).
____ / 4 = 4 r2
DIVISOR: 4
QUOTIENT: 4 r2
DIVIDEND: missing
SOLUTION: 4 x 4 + 2 = 18