Basic Rules for Spreadsheets

Presented: May 27, 2003
by John Hicks

Notes for Basic Spreadsheet Equations:

Note that each equation MUST begin with an equal sign (=), and must be completed by hitting the Enter key on the keyboard.
Note also that the multiplication sign used is the asterisk (*) and the division sign is the forward slash (/).

In the following table, the numbers which have been entered as examples are in column C, and in rows 6, 7, 8, 9, and 10. Thus, each number has a cell "address"; for example, the first number ("100") is located in cell C6, the second number ("300") in cell C7, and so forth:

Dealing with a Series of Numbers:

Addition:

In order to add together the numbers in cells C6, C7, C8, C9 and C10, one way is: to type the following equation (for example, into cell C11):

= C6+C7+C8+C9+C10 {ENTER}

OR: you could use the SUM function, by typing the following:
=SUM(C6..C10) {ENTER}

OR: you could highlight these five numbers, as well as an empty cell (like C11) which is below them in the same column, and click on the summation icon (Σ, which looks just like the uppercase Greek letter sigma).

In any case, you should get "1200" as the answer.

Mixed numbers:

If you want to perform more than one type of operation, you have to remember that the computer does certain operations first, regardless of the order of the elements involved. For example, type the following formula into a cell:

=(C6+C7) +C8*C9/C10 {ENTER}

Using the five example numbers listed above, the answer will be 493.75. How do you get this result? Computers consider operations in the following order:

Brackets ( ), then division( / ), then multiplication ( * ), then addition ( + ), then subtraction ( - )

Using the example numbers given above, the formula looks something like this:
(100 + 300) + 250 * 150/400
The computer does the computation as follows:

Original formula(100 + 300) + 250 * 150/400 Brackets(400) + 250 * 150/400 Division400 + 250 * 0.375 Multiplication400 + 93.75 Addition493.75 Subtractionnone Final Result493.75

Average a series of numbers:

To average a series of numbers, use the AVERAGE function, as follows:
=AVERAGE(C6..C10) {ENTER}

The result is: 240

More information on spreadsheet use is available on the following web pages: