Pythonista still uses Python 2, where the default behavior for division can be a little confusing. If at least one operand is a float, then the division will work normally and return a float. If both operands are ints, then Python does "floor division" and rounds down the result to an int. This is also how languages like C and Java behave (which is why Python originally did too).
In Python 3, division always returns a float. To get the same behavior under Python 2, you can put the line from __future__ import division at the top of your program. The division behavior for the interactive console can be changed in the Pythonista settings.
By the way, if you want to use floor division on purpose, you can use the // operator, which exists on Python 3 and recent versions of Python 2. For example 5.0 / 2.0 == 2.5 and 5.0 // 2.0 == 2.