SpeedCrunch is a high-precision scientific calculator. It features a syntax-highlighted scrollable display and is designed to be fully used via keyboard. Some distinctive features are auto-completion of functions and variables, a formula book, and quick insertion of constants from various fields of knowledge. Available for Windows, OS X, and Linux in a number of languages. When you first launch SpeedCrunch you might be tempted to use it like an ordinary pocket calculator, that is punched with your mouse on the keypad to produce results.
But SpeedCrunch has been developed with fast keyboard usage in mind. Of course, at your option, you may stick to a mouse and graphical elements for input, but the recommended way is typing in your expressions. This program is free for download, please visit the official website for downloading. www.speedcrunch.org