You could have downloaded Beaconaut APICalc 2.0 from our software library for free. The actual developer of the program is Beaconaut Communications. The most popular version of the tool 2.0. APICalc200.exe is the default file name to indicate this program's installer. The software relates to Office Tools.
From the developer:
In computer science, arbitrary-precision arithmetic is a technique whereby calculations are performed on numbers whose digits of precision are limited only by the available memory of the host system, It is also called bignum arithmetic.
Arbitrary precision is used in applications where the speed of arithmetic is not a limiting factor, or where precise results with very large numbers is required.
You may want to check out more software, such as Gestational Age Calculator, JD8Calc or SCalc, which might be similar to Beaconaut APICalc.