iWork '09: The Missing Manual

Chapter 20. Using Formulas

Just on its own, a grid is good. You’ve got your data organized and sorted, all in one place. And now that you know how to build and style this baby, you can show it off with panache. But your table doesn’t do much yet. Isn’t a spreadsheet supposed to balance your checkbook, manage your company’s budget, make you dinner, and find you true love? Although Numbers might not offer any love potions, it does have all kinds of other formulas to set your grid in motion.

In Numbers, formulas are responsible for the fundamental numbers work behind your spreadsheet, mixing and mashing your raw data to surface facts, figures, and bottom-line tallies. Formulas are equations that you add to cells to make them calculate: add up columns, average grades, or figure the net present value of an investment. A formula’s calculations can range anywhere from very simple math (1+1) to complex constructions that gather values from other tables or apply sophisticated financial algorithms. This chapter gets you started at the shallow end of that pool, getting you acquainted with Numbers’ basic arithmetic before you move onto the gee-whiz formula magic you’ll find in the next chapter.

Whether your math is simple or sophisticated, Numbers makes the process of adding and editing formulas easy, giving you lots of ways to build and insert these number-crunching gizmos into your table cells. You can compose an elaborate formula by hand, sure, but you can also drag-and-drop common calculations ...