Another look at that spreadsheet

We often neglect the unique power that computers give to normal people: total control over numbers. If you don't know how to use a search engine, you can still go to a library to look things up. Absent online retailers, you can still order from a catalog. I can guarantee you that not one person in 1,000 can calculate mortgage payments with a pencil and paper.

Thus, now that this column has spent some time on communication, we're going to turn to calculation, both the kind you do on your PC directly, and some of the new stuff on the Web.

Our first order of business is to get you interested in spreadsheets. You may never be a spreadsheet jock, but it is still worth spending a couple of weekends playing with the one that came with your computer. Most PC bundles include Microsoft Works, and Works incorporates a reasonably powerful spreadsheet. Using a spreadsheet can be a reach, mentally. So this most basic of tools for math is widely neglected by normal folk.

Which is too bad. Once you get the hang of it, a spreadsheet is a lot easier to use than a calculator or pencil and paper. Even if you're an idiot at math, you can perform prodigious and sophisticated calculations, one step at a time. As with word processing, you can rewrite, rearrange and generally fiddle until you get the formulas and the answers you want. Only in the case of a spreadsheet, you'll be plugging in new numbers -- mortgage rates or terms, for example -- and getting instant answers. If I had my way, every high school in America would teach a basic two-week course on spreadsheets.

The stationery and task wizards that accompany Microsoft Works can give you some idea of how a spreadsheet works: They'll calculate mortgage payments for you, write bills and set up bids, among other things. They're worth playing with, but the fancy formatting tends to obscure the real flexibility of spreadsheet programs. And besides, if all you want to do is use some canned calculators, you'll usually find better stuff available on the Web, which is what we're going to look at next week.

This week, though, we're going to show you how to use a spreadsheet like a blank piece of paper. We're not going to be able to teach you everything you need to know here -- you can spend weeks learning fine points and shortcuts from your help system and manuals -- but we'll get you started. Start up Works, select the Tools tab, then select the spreadsheet option.

What you see in front of you is an unformatted spreadsheet -- a simple grid of lines.

Across the top of the grid are letters: A, B, C, etc. These refer to vertical columns.

Down the left side are numbers, which correspond to horizontal rows. The grid forms boxes called cells. Each cell has a unique address based on the intersection of its row and column. Thus the first cell in the upper left corner is Column A, Row 1, and will be known to the computer as A1.

The key to understanding a spreadsheet is understanding that you use these coordinates to manipulate numbers by creating formulas. On a calculator, you enter ''2 plus 2,'' hit ''equals'' and get ''4.'' On a spreadsheet, this takes a couple of extra steps. Type 2 into cell A1, and 2 into cell A2. Then you enter your formula into the cell where you want to have the answer displayed, A3. Microsoft Works uses slightly different formulas. Poof, the formula disappears from the cell and the answer, 4, is displayed.

One of the things you may find confusing about your spreadsheet, particularly if you've cut your teeth on word processing, is that your cursor seems to be in two places at once -- within the grid, and up above the grid in a little one-line window, which displays the formula as long as you're using it. In effect, you have one cursor for navigating among the cells and one cursor for editing the formula in the little window.

Why would you want to go to all that trouble to add 2 and 2 when you could do the same thing on a calculator? For one thing, you can label the numbers by typing text into the adjoining cells: ''Apples'' in B1 and ''oranges'' in B2. Or change the first 2 to 5. Voila, instant new answer of 7. Unlike a calculator, into which you must enter all the numbers every time you want an answer, you can reuse your formulas and often most of your numbers. Or you can add new formulas to further refine your numbers.

In other words, you're doing what computers do best: designing a tool that, with minor changes, will let you take on a whole series of calculations. You could do it by hand, rather than computer, but it would be tedious and error-prone.

Estimating and budgeting is another area where spreadsheets shine. Suppose you're planning to renovate your kitchen, and that you'll be acting as your own contractor and maybe do some of the labor yourself. You know how much you want to spend, and you have bids for plumbing and wiring.

So you set up a list of items that calculates a total cost for the project. Now you can take all the other variables -- floor covering, cabinets, lighting, new windows, appliances -- and plug them into the list.

Within the list, you can create subcalculations -- you know you have 500 square feet of flooring to cover, so you create a cell that calculates the cost of wood flooring at $3.25 per square foot. When all the numbers add up, you notice you still have a few hundred dollars left in your budget.

Now you can quickly plug in alternate floor coverings and their costs, or better appliances, or cabinet upgrades, and quickly see how they affect your bottom line.

Mortgages and loans are a little more complicated, because you may have to use some of the built-in computational formulas of the spreadsheet. Again, they help you make better decisions. Sit there and noodle with the numbers: What if you get a 20-year term rather than 30 years? Or 15 years? Or how much more money will you save in the long term if you're willing to spend an extra $100 a month on the loan? Plug the loan calculator into your cost estimator, and you'll get an instant read-out of how much a month it costs to put in marble floors instead of carpeting.

You can create spreadsheet stationery, too. I have formatted spreadsheet stationery to look exactly like an expense-account form. I use my numeric keypad to enter phone charges in a cell that automatically adds them up, then calculates the tax on that portion of my phone bill. These numbers and others are carried through to the bottom line, where they are added together automatically. Other spreadsheet stationery calculates mileage reimbursement by automatically multiplying allowable cost per mile times the number of miles I've driven.

Next week, we'll look at some of the alternatives to spreadsheets that you'll find on the Web.

Distributed by the Los Angeles Times-Washington Post News Service