print floating point number

[snippsat]

Is that what's causing the floating point numbers to print incorrectly? How can I start running 3.4?

Yes,and install 3.6 Python 3.6 and pip installation under Windows also part 2.

Btw, I don't understand what this suggestion means: "Add a dot 18. and it magically work."

You make it float bye adding .,then it work for Python 2.

c_n = float(((12*n + 5)/(3*n + 18.)))

>>> n = 18
>>> type(n)
<class 'int'>
>>> n = 18.
>>> n
18.0
>>> type(n)
<class 'float'>