Introduction: RedCrab is a highly efficient calculator that will enable users to work in fullscreen mode. Several mathematical functions can be written on the same page. Results from one expression can be carried over to the next task. You can save and load the formulas to create a formula library.
 Red Crab  Red Crab File
 Red Crab Edit  Red Crab Insert
 Red Crab Tool Box  Red Crab Function Panel

If you are doing math and don't have a TI Programmable Calculator, you are at a disadvantage.
Texas Instruments TI-83 Plus Graphing Calculator; 64 H x 96mm W Screen