Navigating an Equation

Now let's change E = mc² to E = 1 + mc². Use the arrow keys to move the cursor into the expression. Note that when you enter the expression, the purple markers appear to let you know you're editing math. Now you can use Left and Right to move the cursor past the equals sign, and just type ``1+''. Again, you can use the arrow keys or Esc to leave the formula.

Other than the special keys described below, typing in math mode is like editing regular text. Use Delete (or Backspace) to delete things. Select text either with the arrow keys or with the mouse. Edit $\triangleright$Undo works in math mode, as does cutting and pasting. One thing to be careful of: if you're right outside a Mathed expression and you type Delete (or Backspace), it will delete the whole expression. Luckily, you can just use Undo to get it back.

What if you want to change E = mc² to E = mc^2.5 + 1? Again, you can use the mouse to click in the right place. However, you can also use the arrow keys. If the cursor is just after the ``c'' but before the ``2'', then typing Up will move the cursor to the level of the superscript, just before the ``2''. Add the ``.5''. Now, hitting Down will move the cursor back to the regular level. In fact, if you hit Down from anywhere within the superscript, the cursor will be placed just after the superscript (so that you can then type the ``+1'').