Qalculate! is a powerful yet user-friendly math software that provides practical currency conversion and percent calculation tools. It offers a vast library of customizable functions, unit calculations and conversions, physical constants, symbolic calculations (including integrals and equations), arbitrary precision, uncertainty propagation, interval arithmetic, and plotting.

The software offers an expression entry method that allows you to input mathematical expressions naturally, just as you would write them on paper. Once you hit Enter, the program will interpret your expression and provide the result. Qalculate! is lenient and can handle mistakes. However, if you enter an expression that is not fully recognized or ambiguous, it will provide a helpful warning or error message with information to correct it. If an expression cannot be entirely solved, Qalculate! will simplify it as much as possible and respond.

Expressions in Qalculate! can include variables, units, functions, numbers, and arithmetic operators. These can be easily accessed through the user interface by utilizing the automatic completion feature or navigating the menu bar, object managers, or calculator keypad.

Additionally, Qalculate! provides several specific tools for your convenience, such as a number-based conversion dialog and a simple plotting interface.
While Qalculate! is designed for simple calculations, it's still helpful to review the manual as it contains valuable information.

Qalculate! includes numerous features that can be viewed in their entirety here.

Qalculate! Portable is also available.

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