Hi! Since there is no stated question, I need to guess: n -= 1 (instead of "f -= 1") should work. Or maybe the question was a totally different one... -Kimmo 11.01.2013 17:35, kwakukwatiah at gmail.com wrote: > def factorial(n): > if n<2: > return 1 > f = 1 > while n>= 2: > f *= n > f -= 1 > return f > > >