Remember using formulas to calculate math problems in school, like 2+2=4, or 2 pizzas
x $10 dollars = $20?
You can use these same formulas to work with numerical data in your spreadsheets, just
like you would use a calculator.
Excel uses standard operators for math equations, like a plus sign for addition; a minus sign
for subtraction; an asterisk for multiplication; a forward slash for division; and a caret
for exponents.
You're probably used to seeing equations like 5+5=, but in Excel, the equals sign comes
first. That's because the cell itself contains (or is equal to) the formula and its value.
Let's start off with a simple addition formula. We're going to calculate the total budget
for June and July. However, instead of entering these numbers (in other words, $1200+1500),
we're going to use cell references. Here's how it works.
First, select the cell where you want the total to appear, then type an equals sign,
which is how you always start a formula. Next, type the addresses of the cells you want to
add; in this example, D10+D11.
Notice how the cells you've entered are actually highlighted in your worksheet, so you can
easily confirm the contents of your formula. When you're ready, press Enter on your keyboard...
and Excel will display the answer.
Now, you may be wondering why we used cell references instead of numbers. It's because
they give you the ability to change your original values... without having to re-type your formula.
Excel automatically recalculates the answer so it's always up-to-date. For that reason,
you should try to use cell references whenever you can.
To edit your formula, all you have to do is double-click the cell. If you make a mistake
or you change your mind, you can press Esc on your keyboard... and it'll go back to the
way it was.
Let's try another example, this time with multiplication. I want to calculate the total
price for plastic silverware... so I'll need to multiply B4 by C4. Once again, start by
typing an equals sign... but instead of entering the addresses manually, we're going to use
something called the point and click method.
Just click the cell you want... and the address instantly appears in your formula. Most people
find this much easier than typing out the cell addresses by hand. When you're done,
press Enter... and the answer appears.
Finally, I want to show you a quick way to add a formula to several cells at once—specifically
these three cells. Instead of re-typing the formula above, we're just going to select
the first cell... then locate the fill handle in the bottom right corner.
Click and drag the handle down, and when you let go... the formula appears automatically
in all three cells. Now we can see the total cost for each item. This is a great shortcut
for duplicating formulas if you plan to use the same one more than once.
Formulas really are one of the most powerful and convenient features in Excel. Now that
you know how to use them, they can help you calculate all kinds of useful data.