[ Thanks to LinuxLinks for this link.
]
“One of the basic utilities supplied with any operating
system is a desktop calculator. These are often simple utilities
that are perfectly adequate for basic use. They typically include
trigonometric functions, logarithms, factorials, parentheses and a
memory function.“However, the calculators featured in this article are
significantly more sophisticated with the ability to process
difficult mathematical functions, to plot graphs in 2D and 3D, and
much more.“The calculators also typically support the Reverse Polish
notation (RPN). This is a prefix notation wherein every operator
follows all of its operands. In other words, instead of pressing 6
+ 8 and the enter key, in RPN you type in 6 8 +.“Occasionally, the calculator tool provided with an operating
system did not engender any confidence. The classic example being
the calculator shipped with Windows 3.1 which could not even
reliably subtract two numbers. Rest assured, the calculators listed
below are of precision quality.”