But here are some that I think are useful: formulas, related items, and calculations built into Edit > Paste Special.
FORMULA -- you can display the formula for any cell.
=FORMULA(B6) shows you the formula from B6.
To copy and paste only cells that contain formulas, copy, then choose Edit > Paste Special. Select only Formulas and click OK.
Paste Special, using the Operations section.
You can add, subtract, multiply, or divide values of one set of cells with another.
- Select the other set of cells and choose Paste Special.
- In the window that appears, choose All in the left column, then under Operations choose Add.
- Click OK.
- The cells you copied are added to the cells you pasted.
ISBLANK returns TRUE if a cell is blank.
This isn't as flashy, but ISBLANK(cellreference) or ISBLANK(cellrange) can be used for error checking or just seeing if you've got blanks where you shouldn't. For a cell range, it would be something like =ISBLANK(A5:A55).
INFO is a slightly obscure but perhaps useful formula.