I am a bit confused about modular arithmetic. We say that two integers are equal modulo n if their difference is an integer multiple of n.
So let's take as example: $5(mod2) = 1$, since $5-1 = 4$ which is an integer ($k$) multiple of 2.
But isn't this also true then: $5(mod2) = 3$? Because $5-3 = 2$ which is also an integer multiple of 2, namely $k=1$. If this is true, then why does a calculator just give $5(mod2) = 1$?
Same for $-2(mod7)=5$, why do we pick 5 if there are infinitely many equalities?