AssertionError: 5 != 1 :
def square (number): return number * 5
Steven Parker194,826 Points
The message may be a little confusing, but the instructions asked for a function that would square the passed argument, but that's not what this code is doing.
One way to calculate a square would be to multiply the value by itself, but multiplying by 5 would only create a square if the argument was also 5 (and the tester obviously tries other values).