SpeedCrunch is a fast, high-precision scientific calculator. It features a syntax-highlighted scrollable display and is designed to be fully used via keyboard.
It includes many built-in maths functions and supports advanced features like user-defined functions, complex numbers, and unit conversions. This is combined with a simple yet powerful user interface featuring on-the-fly results preview, syntax highlighting, and autocompletion.
SpeedCrunch is available for several platforms in a number of languages.
Screenshots

Install
If this does not work, see FAQ#1
If this button doesn't work, see FAQ #1
How to install?
Screenshots
Sites
Sources
Exact match
Name match
Description match
No applications found
No applications found matching "{0}"
Try selecting "All architectures" or broadening your search keywords.
Check for typos or try searching with different keywords.
Clear search
{0} results
Failed to load apps.