76
Work out the prime factors: 4: 2x2 19: 19 (it's prime) None of the factors are shared so the answer is 2x2x19 = 76 (which is also 4x19 but it's not always that straightforward though).
0x19=0 1x19=19 2x19=38 3x19=57 4x19=76 5x19=95 6x19=114 7x19=133 8x19=152 9x19=171 I will add more tommorow but this is all for today BYE
81/19 = 4.263 (approx).