Microsoft Office Tutorials and References

In Depth Information

**Adding a Column of Numbers**

Let’s take note of what we’re looking at. Clicking the AutoSum button in H8 installs the

expression shown in Figure 4–3. This expression uses Excel’s built-in

SUM

function:

=SUM(H3:H7)

And what is that expression telling us? It’s telling us that Excel plans to add all the

values in the range H3:H7. Press Enter and you’ll see the result, 267, in cell H8. Voila!

This expression is called a
formula
(you can tell a formula because it starts with an equal

sign (=), and this formula displays the result of the

SUM

function. You can read the

formula as “The contents of this cell equal the result of the

SUM

function.” In the

“Customizing the Worksheet with Formulas” section later in this chapter, I will teach you

how to write formulas from scratch. For now we are going to use the built-in functions,

which make writing formulas quick and easy (and it’s the functions that we really care

about, because they do the hard work for us).

NOTE:
If you
double-click
the AutoSum button, it will display its result immediately in its cell,

without stopping to reveal its formula as in Figure 4–3.

Now type
in cell H4, replacing the original 67. Cell H8 will now show 271. This
71

demonstrates what’s perhaps the single greatest contribution of spreadsheets to

Western civilization: automatic recalculation. Once a formula has been placed on a

worksheet, any change in the values used in the formula will immediately change the

formula’s result. There’s no need to rewrite the formula—it delivers the new result

automatically. Just change the contributing values, and the answer changes.

Returning to our example, we see that it works because

is programmed to add all

the values in the cells directly above it (or to its left, if you’re adding values in a row); that

is, it adds the cells that actually
contain
a value. And that means that if we had

encountered this range shown in Figure 4–4 in H3:H7 instead, and had clicked AutoSum

again in H8, we’d have seen the result shown in Figure 4–5.

SUM

Figure 4–4.
Something’s missing: Adding (or trying to add) the values in this range