Today we talk about the rules of arithmetic in Python Version 3. The key detail is when combining two numbers, Python will widen numbers to make sure they are all of the same type. (In Python v3, there are three numeric types: ints, floats and complex numbers.) And division has changed from version 2. Now, division always returns the correct math value as a float. It no longer returns the quotient when you divide two whole numbers. And beware of division by 0!