For example, consider the real numbers
To truncate these numbers to 4 decimal digits, we only consider the 4 digits to the right of the decimal point.
The result would be:
Note that in some cases, truncating would yield the same result as rounding, but truncation does not round up or round down the digits; it merely cuts off at the specified digit. The truncation error can be twice the maximum error in rounding.
For negative numbers truncation does not round in the same direction as the floor function: truncation rounds toward zero, the floor function rounds down.