Microsoft Office Tutorials and References

In Depth Information

**Considering Form versus Function**

If you used a formula
, you might enter

=C5+C6+C7+C8+C9 in cell C10 to display the

total of those cells. Although entering this

formula is not particularly difficult, it is tedious.

Instead of typing such a formula, you can use

the SUM function to get the same results much

more quickly. As you can see in Figure 3-1, the

function =SUM(C5:C9) is entered into cell C10

to compute the total you need.

For example, there’s a PMT function you can use

to calculate monthly payments on a loan. You

feed the PMT function an interest rate, total

number of payments over the life of the loan, and

the loan amount, and presto! The PMT function

calculates the amount due each month.

And the fun doesn’t end there: using the PMT

function, you could compare the interest rates

on various loans of particular amounts, and

purchase prices of several homes in your area, and

quickly identify which home is the best deal for

you. If you had to work manually, computing

these same payment amounts would be difficult

and time-consuming, and by the time you figured

things out, somebody else might have already

bought the home of your dreams.

You learn to enter a function properly in the

next section, “Understanding Function Syntax.”

For now, let’s concentrate on the basics. Again, a

function is a pre-programmed formula. You feed

a function some data, such as a range of cells, and

it spits out an answer, such as the total of the

values in those cells. What kind of data, you ask?

Not to worry: when you enter a function, Excel

provides you with a wizard that assists you in

filling in the blanks so you won’t fail to provide

the function with some needed data.

Obviously, the SUM function is pretty simple,

and something you might be able to do without

in situations where you are adding the contents

of only three or four cells. But try adding up a

long column or a range of cells using a regular

formula, and you will soon tire of typing all those

plus signs between cell addresses. In addition to

the SUM function, Excel provides many other

functions, grouped into various categories such

as Financial, Lookup & Reference, and Math & Trig.