[GNC] Bill total does not match real total

[Fred Tydeman]

Actually, DFP (decimal floating point) has been part of gcc since 2005.
DFP is now part of standard C (C23).  DFP was first proposed for C in 2003
N1016 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1016.htm> 01-Sep-2003
Mak, Extension for the programming language C to support decimal
floating-point arithmetic

Intel 8080 and x86 CPUs both have a limited instruction set for BCD
(binary coded decimal).

The first computer I ever used (in 1967), the IBM 1620, used BCD
floating-point.