Think of it this way, if you have a number:
3.14159265359
If you want to trim down the precision of this floating point number, what you do is fairly simple.
Let's say you want only 5 decimal places, you first multiply this number by 1*10^5, or, 100,000:
314159.265359
Now you round it to the nearest whole number with the round operator.
314159
And finally divide it by that same 1*10^5 (100,000):
3.14159
And voila, you have trimmed off a few decimal places. You can even do this all in one handy equation:
(round(3.14159265359*100000))/100000
If someone could only clarify whether or not the float() operator needs to be used. This above is a pseudo implementation, but in theory that's exactly what you would do to trim your precision.