Section: Copying and Pasting formulas
...Subsection: Steps for using formulas

Decide what you need the formula to do

This sounds obvious, but it's the first step in the STAIRS technique for a reason. Make sure you know what you're up to; randomly typing in numbers won't get you very far.

Write the formula once

Write the formula in the first spot you need it.

Convince yourself it works

Make sure it works. Try it out with weird data. Make sure you fully understand what it's doing and what data it's working with.

Copy the living tar out of it

Once you've written a formula that works, abuse it!

• Select the cell with the good formula
• Choose Edit:Copy to put it on the clipboard
• Use the mouse to select all the other cells where you need that formula
• Choose Edit:Paste