LECTURE NOTE 02

CREATING SIMPLE FORMULAS

Formula. A formula is a group of symbols that make a mathematical statement. A formula can be a combination of values (numbers or cell references) and math operators (+, -, /, *, =) into an algebraic expression. Excel requires every formula to begin with an equal sign (=).

The following table illustrates the mathematical operators learned in school and those represented in Excel 2003. | |School |Excel 2003 | |Addition |+ |+ | |Subtraction |- |- | |Multiplication |X |* | |Division |/ |/ | |Equals |= |= |

The result of a formula-the answer to 2+3, for example-displays in the cell on the Excel worksheet. The formula is visible only in the formula bar. A formula's result will change as different numbers are entered into the cells included in the formula's definition.

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CREATING A SIMPLE ADDITION FORMULA

A simple formula in Excel contains one mathematical operation only: one number plus a second number equals a third number. Writing a simple formula is really no more difficult than that: 1+1. The only difference in Excel is that all formulas must begin with the equal sign (=). It is not enough to type 1+1 in Excel because what will appear in the cell is "1+1." You must begin the equation with an equal sign, or =1+1. This holds true for any formula, simple or complicated, that adds, subtracts, multiplies or divides. Let's add two numbers to create a third, 128+345=473. In Excel, this would be expressed by the formula, =128+345, as shown below.

To Create a Simple Formula that Adds Two Numbers:

• Click the cell where the formula will be defined.

• Type the equal sign (=) to let Excel know a formula is being defined. • Type the first number to be added (128, for example) • Type the addition sign (+) to let Excel know that an add operation is to be performed. • Type the second number to be added (345, for example • Press Enter or click the Enter button on the Formula bar to complete the formula. But what if a column contains many numbers, each of which regularly changes? You don't want to write a new formula each time a number is changed. Luckily, Excel 2003 lets you include cell references in formulas. A formula can add the value of two cells-B2 and B3, for example. Type any two values in these two cells and the formula will adjust the answer accordingly. Using this method to calculate two numbers-128 and 345, for example-requires that you type 128 in cell B2, for example, and 345 in cell B3. The Excel formula, =B2+B3, would then be defined in cell B4. To Create a Simple Formula that Adds the Contents of Two Cells: • Type the numbers you want to calculate in separate cells (for example, type 128 in cell B2 and 345 in cell B3). • Click the cell where the answer will appear (B4, for example). • Type the equal sign (=) to let Excel know a formula is being defined. • Type the cell number that contains the first number to be added (B2, for example). • Type the addition sign (+) to let Excel know that an add operation is to be performed. • Type the cell number that contains the first number to be added (B3, for example). • Press Enter or click the Enter button on the Formula bar to complete the formula. ----

CREATING A SIMPLE SUBTRACTION FORMULA USING POINT-AND-CLICK METHOD

Formulas can be created by using either numbers or cell references in the definition. You can also use the mouse to select the cells to be used in the formula instead of typing the cell number or cell reference....