Ruby Language Numbers Rounding Numbers
Example
The round method will round a number up if the first digit after its decimal place is 5 or higher and round down if that digit is 4 or lower. This takes in an optional argument for the precision you're looking for.
4.89.round # => 5
4.25.round # => 4
3.141526.round(1) # => 3.1
3.141526.round(2) # => 3.14
3.141526.round(4) # => 3.1415
Floating point numbers can also be rounded down to the highest integer lower than the number with the floor method
4.9999999999999.floor # => 4
They can also be rounded up to the lowest integer higher than the number using the ceil method
4.0000000000001.ceil # => 5
