Theorem 1.1 The Division Algorithm:
Let a, b be integers with b > 0. Then there exist unique integers q and r such that a = bq + r
and 0 < r <b.
Let a and b be integers with b not equal to 0. We say that b divides a (or that b is a divisor of a,
or that b is a factor of a) if a=bc for some integer c. In symbols, “b divides a” is written b | a.