Ok, sorry for me being a noob, but I am only high school standard ¬__¬
Anyways, say you have Z16, why can't this be a field? Let 16=i, u say that m*n = i, so 2x8 = 16. And 2x8 = 0 (modulo 16), and then you say fields are not allowed to have zero-divisors. But I am not dividing by zero...
Also...