Quick guide
How to use this calculator
- Enter a finite decimal.
- Choose 0–100 decimal places.
- Read the value after discarded digits are removed without nearest rounding.
Calculation method
Discard rather than round
The exact scaled integer is divided by the target power of ten with its remainder removed toward zero. For negative input, this differs from floor.
Worked example
Truncating a negative value
Removing all fractional digits moves −1.9 toward zero, not toward negative infinity.
trunc(−1.9) = −1
Supported inputs
Precision and limits
Exact decimal input
Finite decimals use integer-scaled arithmetic, with no binary floating-point conversion.
Input boundary
Unless stated otherwise, use at most 200 digits total and 100 digits after the decimal marker.