Microsoft Office Tutorials and References

In Depth Information

**Ordering Up Your Results**

=4*(5+7)

You get the idea. Excel resolves this kind of ambiguity with a set of orders of operation—a kind of

priority listing which declares which operation takes precedence—that is, is calculated first—in a

formula. (In the cases above, the values flanked by parentheses are treated as a unit.) The order reads

like this:

Parentheses

Exponents

Multiplication

Division

Subtraction

Addition

Let’s illustrate this hierarchy with a few cases. This formula:

=4+5/2

results in an answer of 6.5. It divides 5 by 2 and
then
adds 4—because priority goes to division over

addition.

This formula:

=4*5/2

results in 10, because the
multiplication
—4 times 5—is carried out
first
. That result—20—is then

divided by 2.

This formula, however:

=4*(5/2)

also yields 10, but this time because the parenthetical expression—(5/2) that is, 2.5—has priority over

any other operation.

Now let’s get back to our regularly scheduled program—this matter of adding numbers via a

formula. While the method we recounted above surely works, it conceals a problem. What if you need to

add 20,000, or even 200, numbers? You won’t want to click on each and every one of those cells as per

our initial method—and, given Excel’s cell character limit, you may not be able to do it anyway. So

what’s the alternative?

Good question. The answer takes us to the first and most important of Excel’s built-in operations, or

functions
, called
SUM
. How does SUM work? For introductory purposes, we’ll demonstrate the standard

way to implement SUM in a worksheet—with the
AutoSum
command, which is actually stored in two

different tabs (remember that term?) in slightly different guises—
Home
and
Formulas
, shown in Figures

3–4 and 3–5:

Figure 3–4.
The location of AutoSum in the Home tab