The mathematicians we know tend to classify operations into two types: binary and unary. Binary operations require two numbers. We are familiar with such examples as 2 + 4. This has two numbers and a single operation. The unary operations are the types of operations where a number does something to itself. An example might be the square root of 4 or 3 raised to the second power. Most of the time we use the "binary" type operation and these operations are so common in their use, we call them the "four basic operations."
A quick review of some basic facts is in order.
Excel allows you to direct the four basic operations of arithmetic to happen on numbers. These operations include addition, subtraction, multiplication, and division. The standard symbols you might expect for addition and subtraction (+ and -) are used to indicate the operation. Multiplication and division are slightly different than what you might use with pencil and paper or typewriters.
The asterisk ( * ) is used to indicate multiplication. That is, the "X" in the familiar 2 X 3 is replaced with 2 * 3. The asterisk is the ONLY symbol Excel will recognize as multiplication. It is common convention to replace the X in the expression 3 X (A + 5) and use 3(A + 5). It is "understood" that the positioning of the 3 up against the left parenthesis means to multiply....but not to Excel. You would have to enter 3*(A + 5) to get Excel to understand multiplication is indicated.
We have several ways of indicating division. Each of the four samples represents division with a different symbol.
 |
3  7 |
 |
 |
7
divided by 12 |
3
divided by 7 |
3
divided by 7 |
15
divided by 3 |
Comments:
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Excel, like other computer programs, requires operations to be entered on a single line. This would eliminate the first choice.
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The second choice is eliminated because you have no keyboard symbol. Long time ago, you could type on a typewriter a colon (: )and backspace and type a dash ( - ). Today, with computer keyboards, the backspace key will erase the colon!
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The third choice contains all that is necessary for entry of division from the keyboard of a computer. The "slash" key works This will be the accepted symbol for division by Excel.
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The fourth choice fails for lack of a keyboard symbol for division.
Examine the two different slash keys. There is the / (forward) and \ (back) slash keys. Excel recognizes only the / or forward-slash key as division. Excel will understand 5/6 but not 5\6.
Finally, Excel requires some help in making a distinction between the statement of the arithmetic problem and the command to compute the results of the problem. That is, if you enter 1/2 in a cell, should the display be .5 (the results) or should the display be 1/2 (the problem)?
The folks at Excel came up with a code which lets you determine whether you wish to display the problem or the solution. When you wish Excel to actually calculate the results, you precede the problem with an equals sign.
| Problem |
You
Type |
Result |
12/36 |
=12/36 |
.333333 |
6/8 |
=6/8 |
.75 |
9/2 |
=9/2 |
4.5 |
Since square roots and powers were mentioned, let's take a quick visit to these type operations.
The "trick" is to notice the carat or "up" key on the keyboard. It is the Shift+6 on the computer keyboard.
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To indicate 2 raised to the third power, you would enter =2^3 and Excel would calculate this exponent and display 8.
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To indicate 3 raised to the fourth power, you would enter =3^4 and Excel would calculate this exponent and display 81.
The square root process is a variation on this theme. You may or may not remember the relation between roots and exponents, but the square root of 2 is the same thing as 2 raised to the 1/2 power.
To indicate the square root of 2, you would enter =2^.5 or =2^(1/2) and Excel would calculate this exponent and display 1.414213... depending on the number of decimals you set for that cell to display.
For those who have completed some algebra lately, Excel will correctly understand operations like:
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=3^(2/3) as the cube root of 3 squared
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=5^ .123 as 5 raised to the exponent .123
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=5^ 0 as 5 raised to the 0 power or 1
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=3^ -1 as 3 raised to the negative 1 power or 1/3
Important Comment: If your normal life includes the use of powers and roots, this discussion probably wasn't necessary...you probably already knew this. If you get along fine in life without exponents, you will never be using exponents in your spreadsheets. Excel is "strong" enough to handle all the mathematics that you know and YOU can decide how much or how little you will use!