I'm not sure what "math.ceil" is...did you write that yourself? Or did you mean "Math.ceil"?
If the former, I don't know what to tell you. If the latter, then reading the API would tell you:
Returns the smallest (closest to negative infinity) double value that is greater than or equal to the argument and is equal to a mathematical integer.
perusing the rest of the Math
API would let you find the round() method.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors