>> Python will always yield a number x = m%n such that 0 <= x < n, but >> Turbo C will always yield a number such that if x = m%n -x = -m%n. That >> is, since 111 % 10 = 1, -111 % 10 = -1. The two values will always >> differ by n (as used above). Maybe it is an order-of-operations thing.... -111 % 10 = -1 (-111) % 10 = 9 ?