introduction to excel 20021 formulas, functions and references

Introduction to Excel 2002 1

Formulas, Functions and References


This lesson will cover:

• Creating Simple Calculations • Using Cell References• Editing Formulas• Inserting and Using Functions:

• SUM, MAX, MIN, AVERAGE and MEDIAN

• COUNT and COUNTA• IF

• Naming Cells and Cell Ranges

These topics are from Chapter 4 of the text...

Formulas, Functions and References

http://images.google.com/imgres?imgurl=www.microimages.com/getstart/imgs/formula.jpg&imgrefurl=http://www.microimages.com/getstart/ptolemys.htm&h=200&w=205&prev=/images%3Fq%3Dformula%26start%3D20%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN


Using Simple Calculations…

Calculation is the process of computing formulas and then displaying the results as values in the cells that contain the formulas.

Formulas can be simple like:=(4 + 5)*2

Or, they can contain cell references:=(A2+B5)*2

Or, they can use some of Excel’s built in functions:=PI()*POWER(4,2) you could also use =3.1416 *(4^2)

* Remember, that any values that are to be calculated begin with the equal sign (=)

http://www.webopedia.com/TERM/F/formula.html




Since the next topic will be cell references we can start off easy. To use a simple calculation:

• Click the cell in which you want to enter the formula. • Type an equal sign (=). This tells Excel that the following

text is a formula.• Enter the formula.• Press the Enter key.

For example, to use the formula (or calculation) 3.1416 *(4^2), which would be the circumference of a circle with a radius of 4…



Click on cell A1, then enter an equal sign (=) followed by the formula:3.1416*(4^2)…

Note that the same text is being entered into the actual cell.

When you press the Enter key or click the green checkmark on the formula bar:

The formula remains in the Formula bar, but the value displayed in cell A1 is now the result of the formula… 50.2656.




Important things to remember about calculations in Excel workbooks:

• Excel stores and calculates with 15 significant digits of precision, that’s a number like 100,000,000,000,000 or .000000000000001

• Excel calculates stored, not displayed, values. For example, a cell that displays a date as "6/22/2001" also contains a number that is the stored value for the date in the cell. That number is what is actually calculated if it is used in a formula.

• Excel cannot automatically calculate a formula that refers to the cell — either directly or indirectly — that contains the formula. This is called a circular reference. If a formula refers back to one of its own cells, you must determine how many times the formula should recalculate. A circular reference is not a good thing!




By default, Microsoft Excel automatically recalculates formulas when the cells that the formula depends on have changed. You can change when the recalculation will occur:

On the Tools menu, click Options, and then click the Calculation tab. Under Calculation, select an option. Changing this option affects all open workbooks. If you select an option other than Automatic, press F9 to calculate all worksheets in all open workbooks. To calculate only the active worksheet, press SHIFT+F9.



How to use References…

A reference identifies a cell or a range of cells on a worksheet and tells Excel where to look for the values or data you want to use in a formula. With references, you can:• use data contained in different parts of a worksheet • use the value from one cell in several formulas. • refer to cells on other worksheets in the same workbook, • refer to cells in other workbooks• refer to data in other programs

* References to cells in other workbooks are called external references.

** References to data in other programs are called remote references.


Relative References…

When you create a formula, references to cells or ranges are usually based on their position relative to the cell that contains the formula. When you copy a formula that uses relative references, Excel adjusts the references in the pasted formula to refer to different cells relative to the position of the formula.

Below, cell B2 contains the formula =A2; Excel displays the value of cell A2 in cell B2. This is known as a relative reference.

Relative Reference

http://www.webopedia.com/TERM/R/relative_cell_reference.html


Using Relative References…

To refer to… Use…

The cell in column A and row 10 A10

The range of cells in column A and rows 10 through 20 A10:A20

The range of cells in row 15 and columns B through E B15:E15

All cells in row 5 5:5

All cells in rows 5 through 10 5:10

All cells in column H H:H

All cells in columns H through J H:J

The range of cells in columns A through E and rows 10 through 20

A10:E20


Absolute References…

If you don't want Excel to adjust references when you copy a formula to a different cell, use an absolute reference. For example, if your formula multiplies cell B2 with cell A1 (=A1*B2) and you copy the formula to another cell, Excel will adjust both references to match the new locations. You can create absolute references to the cells by placing a dollar sign ($) before the parts of the reference that do not change, as follows:=$A$1*$B$2

Absolute Reference to cell A1 times a Relative Reference to cell B2

http://www.webopedia.com/TERM/A/absolute_cell_reference.html


Mixing Reference Types…

You can mix relative and absolute references in the same cell reference depending on what reference you want to hold constant.

Such as:=$A1*B2

Absolute Reference to column A and Relative Reference to row 1times B2


Switching Between Reference Types …

If you want to change relative references to absolute (and vice versa), select the cell that contains the formula. In the Formula bar, select the reference you want to change and then press F4. Each time you press F4, Excel toggles through the combinations: absolute column and absolute row ($C$1); relative column and absolute row (C$1); absolute column and relative row ($C1); and relative column and relative row (C1).

For example, if you select the address $A$1 in a formula and press F4, the reference becomes A$1. Press F4 again and the reference becomes $A1, and again it becomes A1.


Editing Formulas…

To edit an existing formula:

Click on the cell that contains the formula…

…and then click in the Formula bar to place your cursor in the editing box. You can now edit the text just as you would any other text. Remember to click the check mark or press the Enter key when you are done!



Editing Formulas …

Note that the cells included in the formula become highlighted in colors that match the color of their reference in the Formula bar.

The red X next to the green checkmark is the “Cancel” button. Use this if you have hopelessly messed up a formula…it happens!

The “down” arrow to the right of the red X on the Formula bar displays a list of the recently used functions. But that is another topic…



Editing Formulas …

When you are editing a formula, be careful not to click out of the formula bar and on to the worksheet. If you do you will add the address of the cell you select (see the bottom figure).

This is good if you want to add the address to your formula, and it happens by design.

However, for a novice Excel user this usually is the time to click the Cancel button…


Using Functions…

Functions are predefined formulas that perform calculations by using specific values, called arguments, in a particular order, or structure. For example, the SUM function adds values or ranges of cells, and the PMT function calculates the loan payments based on an interest rate, the length of the loan, and the principal amount of the loan.

Arguments can be numbers, text, logical values such as TRUE or FALSE, arrays, error values such as #N/A, or cell references.

The structure of a function begins with the function name, followed by an opening parenthesis, the arguments for the function separated by commas, and a closing parenthesis.

http://images.google.com/imgres?imgurl=amail.co.uk/wizard.gif&imgrefurl=http://amail.co.uk/myname.htm&h=183&w=190&prev=/images%3Fq%3Dwizard%26start%3D140%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN


Using Functions…

For example:= SUM (A3, B5:B10, C12)

means

add the values in cells A3, B5 through B10 and C12)

A comma separates values and a colon separates the beginning and end of a range of cells. Syntax is another name for structure, so the syntax of the SUM function is:

SUM(number1, number2, ...)

“…” means “and so on”



To Insert a function into a cell:• Select the cell where you want the function to display its results• Select the Insert menu command from the main menu• Select Function. This will display the Paste Function dialog…


The Insert Function dialog box is really a wizard of sorts…at least the gateway to a wizard…after it opens select a Function Category…“Most Recently Used” is selected here, it shows the functions that were used recently by Excel. To view the available functions select a category from the list box and scroll through the function names in the bottom list.


The POWER function is selected here.

As you highlight, or select, function names in the list box; an explanation of the Return value, the Arguments and the Structure of the selected function is displayed.


Selecting the AVERAGE function displays the function wizard. The wizard guesses which cell references you want to use as the function’s arguments. If these are the correct cells click the OK button, if not enter new ones. You can enter a new cell or range of cells by selecting them from the worksheet while the wizard is displayed. This will change the values in the wizard. If you click OK with the current arguments…

Notice that the wizard displays the result of the

function based on the current arguments.


=AVERAGE(E3:E14)

…see the average of the values from cells E3 through E14 displayed in cell F15.


…this is in the wrong place, the Average should be displayed in cell F15…we need to cut and paste the formula…


=AVERAGE(E3:E14)

…just like pasting any cell value...notice the arguments didn’t change.


Syntax: SUM(number1,number2, ...)Number1, number2, ... are 1 to 30 arguments for which you want the total value or sum.

Examples:

• SUM(3, 2) equals 5

• SUM("3", 2, TRUE) equals 6 because the text values are translated into numbers, and the logical value TRUE is translated into the number 1 (False = 0).

Using Functions…SUM



The SUM function can be accessed through the Function wizard as shown earlier, and by using the AutoSum button on the Standard toolbar. To create a sum or total of a range of cell using this feature:• Select the cell where you want to insert the sum and click AutoSum • Excel suggests a formula based on the cells above or to the right that contain numerical values.• To accept the formula, press Enter.• To change the suggested formula (cell references), select the range you

want to total and press Enter.

Using AutoSum Σ

The AutoSum button is located on the Standard toolbar


If you highlight cell E15 on this worksheet and press the AutoSum button, Excel selects the range of cells above it that contain numerical values (E3 through E14). If this is what you want press the Enter button on the formula bar to confirm and enter the formula.

AutoSum button


The SUM formula, =SUM(E3:E14),

now exists in cell E15

The result of the SUM formula is now displayed cell E15


Using Functions…MAX

Syntax: MAX(number1,number2,...)Number1,number2,... are 1 to 30 numbers for which you want to find the maximum value.

Examples:If A1:A5 contains the numbers 10, 7, 9, 27, and 2, then:

• MAX(A1:A5) equals 27

• MAX(A1:A5,30) equals 30



Using Functions…MIN

Syntax: MIN(number1,number2, ...)Number1, number2,... are 1 to 30 numbers for which you want to find the minimum value.

Examples:If A1:A5 contains the numbers 10, 7, 9, 27, and 2, then:

• MIN(A1:A5) equals 2

• MIN(A1:A5, 0) equals 0



Using Functions…AVERAGE

Syntax: AVERAGE(number1,number2, ...)Number1, number2, ... are 1 to 30 numeric arguments for which you want the average.

Examples:If A1:A5 is named Scores and contains the numbers 10, 7, 9, 27, and 2, then:

• AVERAGE(A1:A5) equals 11

• AVERAGE(Scores) equals 11

• AVERAGE(A1:A5, 5) equals 10



Using Functions…MEDIAN

Syntax: MEDIAN(number1,number2, ...)Number1, number2,... are 1 to 30 numbers for which you want the median.

Examples:

• MEDIAN(1, 2, 3, 4, 5) equals 3

• MEDIAN(1, 2, 3, 4, 5, 6) equals 3.5, the average of 3 and 4



Using Functions…COUNT

Syntax: COUNT(value1,value2, ...)Value1, value2, ... are 1 to 30 arguments that can contain or refer to a variety of different types of data, but only numbers are counted

Arguments that are numbers, dates, or text representations of numbers are counted; arguments that are error values or text that cannot be translated into numbers are ignored

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Using the cells shown on the right:

• COUNT(A1:A7) equals 3• COUNT(A4:A7) equals 2• COUNT(A1:A7, 2) equals 4

Remember: Only numbers, dates, or text representations of numbers are counted by this function.

Using Functions…COUNT

** The data type TRUE returns 1, FALSE returns 0, be careful with non-numeric data types!

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Using Functions… COUNTA

Syntax: COUNTA(value1,value2, ...)Value1, value2, ... are 1 to 30 arguments representing the values you want to count.

COUNTA considers a value to be any type of information such as text, dates, times, all number types, error values and logical values (such as TRUE and FALSE). It includes empty text (“ ”), but not empty cells or arrays in its count.

If you do not need to count logical values, text, or error values, use the COUNT function.


Using the cells shown on the right:

• COUNTA(A1:A7) equals 6• COUNTA(A4:A7) equals 4• COUNTA(A1:A7, 2) equals 7• COUNTA(A1:A7, “Two”) equals 7

COUNTA counts almost everything but empty cells and arrays…

Using Functions…COUNTA

** The error type #DIV0! returns 2. The seven main error types return values ranging from 1 to 7, so be careful with non-numeric data types!


Using Functions…IF

Syntax: IF(logical test, value if true, value if false)

Logical test is any value or expression that can be evaluated to TRUE or FALSE. For example, A10 = 100 is a logical expression; if the value in cell A10 is equal to 100, the expression evaluates to TRUE.

Value if true is the value that is returned if logical test is TRUE.

Value if false is the value that is returned if logical test is FALSE.

http://images.google.com/imgres?imgurl=www.soul-concern.co.uk/if.gif&imgrefurl=http://www.soul-concern.co.uk/&h=142&w=150&prev=/images%3Fq%3DIF%26start%3D80%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN



Example:

On a worksheet, cell A10 contains a formula to calculate the current budget. If the result of the formula in A10 is less than or equal to 100, then the following function displays "Within budget” in the cell that contains the function. Otherwise, the function displays “Over budget”.

IF(A10<=100,"Within budget","Over budget")




Example:

In the example below, if the value in cell A10 is 100, then the logical test is TRUE, and the total value for the range B5:B15 is calculated. Otherwise, the logical test is FALSE, and empty text (“ ”) is returned that blanks the cell that contains the IF function.

IF(A10=100,SUM(B5:B15),"")



Defining and Using Cell Names

Naming cells (or ranges of cells) in Excel makes it easier to navigate through your workbook and to understand what the spreadsheet is trying to present. You can use a text name to describe what the cell represents or just make it easier to select from the “Name box”.

**A descriptive name can also be given to a formula to make it easier to understand. For example, the formula =SUM(FirstQuarterSales) might be easier to identify than =SUM(Sales!C20:C30). In this example, the name FirstQuarterSales represents the range C20:C30 on the worksheet named Sales.



Selecting or Moving to a specifically named cell can be accomplished from the “Name box” as shown below…select the name from the drop-down list and that cell or range of cells will become active.



To Define a cell name:• Select the cell or range of cells that you want to name.• Click the Name box at the left end of the formula bar. • Type in the name of the cell(s).• Press Enter.

To name this cell

Type the name here…



To Define a cell name using the Insert menu:• Select the cell or range of cells that you want to name.• Open the Insert menu• Select the Name command• Select the Define command



When the Define Name dialog box appears:• Type in the name that you want to use.• Press the OK button

The “Refers to:” text box shows the cell(s) that you are naming.

You can chose another cell or range of cells by clicking the button at the end of the box. Names can also be deleted from this dialog box by clicking the Delete button.

introduction to excel 20021 formulas, functions and references

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