More Addresses Than the Phone Book—Cells in excel 2010

More Addresses Than the Phone Book—Cells, and How to Get There

Let’s start at square one—literally, by returning to Excel 2010’s blank worksheet, which is what you’ll see when you enter the program, as shown in Figure 2–1:


Figure 2–1. The 2010 worksheet, or at least part of one And, as you scan this rather panoramic scene, we’ll trot out a few more of those have-to-know concepts, ones you’ll need to keep in mind in order to steer your course across all this territory spread out before you. You’re looking at a worksheet—or more strictly speaking, part of a worksheet, an integral part of a workbook. A workbook, simply put, is really Excel’s name for a file, the kind of object you’ll find listed in My  Documents, e.g., familybudget.xlsx. What Microsoft Word calls a document, then, is what Excel calls a workbook.

By default, the workbook is outfitted with three identical-looking worksheets, all of which are represented by tabs (not the kind we explored in detail last chapter) in the lower-left corner of the workbook, as shown in Figure 2–2:

Figure 2–2. Keeping tabs on the worksheets

You can supplement these three start-off worksheets with additional ones if you wish, or delete them (though you can’t delete  all of them, of course; otherwise you’d have nothing left), and you can even hide a worksheet. Why might you need to use  several worksheets? For example, a university professor might want to assign a sheet to each of the classes she’s teaching,  listing each roster of students and their grades on each sheet. And for ease of data entry and review, all the sheets could be designed and formatted identically.

As you can see, the worksheet comprises an enormous grid, criss-crossed by lettered columns and numbered rows. Each  intersection of a column and row is called a cell, each of which in turn bears an address, identified very simply by its unique  combination of column letter and row number. Thus in Figure 2–3 the cell pointer—that thick-bordered rectangle that  gallivants across the worksheet—finds itself in cell C7:



Figure 2–3. Selecting cell C7
You’ll note of course how the respective C column and 7 row headings have changed colors, denoting the current position of  the cell pointer. A little less obvious, though, is the C7 (it’s never 7C, by the way) posted in the upper left of the screen shot. As  you can see, that sliver of space up there, called the name box (and why it’s called the name box is to be explained a bit later) records the whereabouts of the cell pointer; and the two kinds of indicators—the column/row-heading color change and the  name box cell reference—make it easy to know exactly where you’ve situated the cell pointer.

And as for the cell pointer itself, its position marks that point in the worksheet where data will go when you begin to type. Thus  if I type the number 56 in our screenshot, it will be posted to cell C7.
And as we earlier observed, the worksheet is large—very, very large, consisting of 16,384 columns and exactly 1,048,576  rows. Do the math and you wind up with over 17 billion cells, a preposterously huge number that will likely far, far exceed any  purpose you and I might bring to a workbook; and given your computer’s memory allotment, you probably couldn’t fill all  those cells even if you wanted to. Put another way—if I wanted to view the entire worksheet at one time on my screen, I’d need  a display about 800 feet wide and 1.6 miles long, give or take a football field—and try to sit with that in economy class.

And remember just for the record that each worksheet in the workbook boasts another 17 billion cells— so if you need to catalogue the stars in the Milky Way, for example, you’ve come to the right place. Just make sure you get a RAM transplant first.

But you may be bothered by a more practical issue: since we run out of letters at the 26th column— letter Z, that is—what do  we call column 27, for starters? Answer: That column is assigned letters AA, followed by AB in column 28, etc. Sidle over to  the 53rd column and you get BA, and so on. By the time you puff into column 701—ZZ—your next stop is AAA, with the  lettering finally coming to rest at XFD— the 16,384th column. Thus an address such as LPW34734 is perfectly legal, even if  you never park your mouse in that cell—and you probably never will.