Description has a rounding error.

Ah, good to know, guess I'll stick with my habit of wrapping things with int() then. Thanks!

FWIW it looks like this beast uses a 2.7 flavour of python: http://www.codewars.com/docs/python-environment but it's still good to know of these changes in later versions of python.

Hrm, that's weird, here's my output with ipython:

In [27]: 3 / 2
Out[27]: 1

In [28]: 3 / 2.0
Out[28]: 1.5

In [29]: import sys

In [30]: print(sys.version)
2.7.6 (default, Sep  9 2014, 15:04:36)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.39)]

In [31]: import platform

In [32]: platform.python_version()
Out[32]: '2.7.6'

int(floor(x / 2))

int() will already 'floor', so the use of floor is redundant?

I used int but just now realized that too wasn't necessary since:

3 / 2 = 1

It's only when you specify it as a float that it will return a float:

3 / 2.0 = 1.5

Maybe you missed this requirement?: (we arbitrarily only allow lowercase letters)