FuzzyMath is a free add-in for the OpenOffice.org Calc application. The component allows using uncertain and approximate values in OpenOffice.org Calc. It means that with FuzzyMath you can perform ordinary arithmetic operations and use ordinary mathematical and financial functions with uncertain values as if they are standard, or crisp, numbers.
FuzzyMath is distributed under GNU General Public License (GPL). Source code, the newest versions of the component and documents are available at sourceforge.net/projects/fuzzymath.