Mathematica Tutorial: Notebooks And Documents - Wolfram Research

194 Notebooks and DocumentsMathematical and Other NotationMathematical Notation in NotebooksIf you use a text-based interface to Mathematica, then the input you give must consist only ofcharacters that you can type directly on your computer keyboard. But if you use a notebookinterface then other kinds of input become possible.There are palettes provided which operate like extensions of your keyboard, and which havebuttons that you can click to enter particular forms. You can access standard palettes using thePalettes menu.Clicking the p button in this palette will enter a Pi into your notebook.