SpeedCrunch lets you work with mathematical expressions. Portable app version available for Windows at the project site.

Features include:

• history and results on a scrollable display
• up to 50 decimal precisions
• unlimited variable storage
• intelligent automatic completion
• fully usable from the keyboard
• more than 50 built-in math functions
• optional virtual keypad to be used with a mouse
• on-the-fly and selection calculation
• customizable appearance
• syntax highlighting and parentheses matching

Operating systems: Windows, Linux, Mac OSX, BSD
Screen libraries: Qt
Platforms: 32 or 64 bit

System Requirements:
Pentium-compatible processor
RAM minimum 32 MB
Hard disk space 16 MB