Processing Decimal Values

By Dietmar Kühl

For typical interactions we are used to processing values represented in decimal. Computers are much more versatile processing using binary representations. As a result it is quite common that decimal values are processed using a binary presentation. Sadly, doing so does cause problems when fractional values are involved.

This presentation explains the representation of floating points in a computer and analyses typical problems encountered when using binary floating points to represent decimal values. It then describes alternative representation, in particular decimal floating point and decimal fixed point, and why these solve the relevant problems.

A decimal fixed point representation is the preferred approach when the number of fractional digits used in an application is known. However, that is often not the case. Thus, the design of a library implementation for decimal floating point is discussed.