How to make Python correctly divide ??? It issues -29 // 5 = - 6 ??? and it should be - 5 !!! It issues -29 % 5 = 1 ??? and it should be - 4 !!! More on discuss.python.org

I point I found rather funny... In mathematical number theory, mathematicians always prefer the latter choice (floor). isn't right (it even says so in the linked Wikipedia article). Number Theorists tend use the method where a mod b gives the least nonnegative representative. More on reddit.com

Integer division is generally a native operation on modern CPUs. To the extent that a programming language is meant to allow programmers to tell a computer what to do, this seems self-defeating. Casting to floats then dividing then casting back may be less efficient than integer divsion. The two operations are not numerically equivalent as information is lost when casting a N-bit int to an N-bit float as the significand will necessarily be smaller than the int to make room for the exponent and sign bit fields. More on reddit.com

Well, first of all, you need to perform the test to see if the user has input 0 for the divisor (the number to divide by) before you attempt the division. Otherwise, you'll hit an error. Fortunately, you can do this by simply rearranging your code. Also, you're defining your dividend and divisor within your function; you don't need to send them as parameters to the function. This, for example, ought to work (note the lack of a def header): num_1 = int(input("Please enter the number to divide by: ")) num_2 = int(input("Please enter the number to divide: ")) if num_1 == 0: print('ERROR! Division by zero is undefined.') elif num_2 == 0: print('Zero divided by anything is zero.') else: remainder = num_2 % num_1 if remainder: print(f"{num_2} is not divisible by {num_1}, there is a remainder of {remainder}.") else: print(f"{num_2} is divisible by {num_1}") NOTE: Edited to address spelling error. More on reddit.com