1. Module 4.2: Calculations

2. Contents Formulas Using cell references Making a printout
Error messages in Excel
Test and improve knowledge and skill
Module Activities

3. Formulas = Cell references: B3, C4, A2 Operators: + - * / ˆ
The format of a formula
A formula begins in the same way as a function with the ‘=’ sign and can contain amongst others the following: =
Cell references: B3, C4, A2
Operators: * / ˆ
Excel has built-in functions for certain general calculations, such as the calculation of the sum or average of a range of values. For other customised operations with numbers you can create your own formulas.
Numbers:
Built-in functions: SUM , AVERAGE, MIN

4. Formulas
Examples
Where a cell reference appears in the formula, Excel uses the value contained in that cell to calculate the result of the formula.
B3*C3
B6-C6
B9-A9
Consider the following examples carefully and see how the formulas in the shaded cells have been put together
B12/60*100
14/100*B14
A19+7/100*A19

5. Entering and copying formulas
Where the same type of calculation is needed in adjacent cells, it is not necessary to type in the formula (or function, for that matter) every time.

6. Using cell references
In formulas (or functions) we use cell references to refer to cells which contain data.
the data in the cells can be changed, but the correct answers will still be obtained
In formulas (or functions) we use cell references to refer to cells which contain data. In this way the data in the cells can be changed, but the correct answers will still be obtained.
constants only if the value will not change.

7. Using cell references
In addition to using a cell reference or address, you can also name a single cell or even a range of cells
Select range
first
Type name in name box OR
=SUM(first)

8. Making a printout
It is a good idea first to use the Page Setup dialog box to make certain settings, before you print.
Scaling to make worksheet fit on page

9. Making a printout
It is important first to check carefully how a spreadsheet will look when printed, before it is actually printed.
Excel 2010
Excel 2007

10. Making a printout
If you wish to print only part of a worksheet, do the following:
Excel 2010
Excel 2007
Hint
Apart from using Scaling, you can also try the following if the spreadsheet will not fit on one page:
• Reduce the character size.
• Adjust the margins.
• Change the column widths.
• Change the page orientation to landscape.

11. Error messages in Excel
#VALUE!
#DIV/0!
#NAME?
#REF!
#NUM!
We have already met the ##### signs that appear in a cell when the column is not wide enough to display the number. The following table summarises the error messages that you may encounter when working with functions and formulas. An error message starts with the hash sign (‘#’).

12. Calculations and Printing
Overview of module
Calculations and Printing
Calculations
Formulas
Format
Typing in and copying
Cell references instead of constants
Names for cells
Error Messages
Data types
Valid arguments
Correct syntax
Printing
Scaling
Gridlines
Print Area
Preview
When deciding on which formula to use, first consider how you would do the calculation with ordinary
numbers.
Remember that the order of operations in a calculation is important. For example multiplication and
division are performed before addition and subtraction. Brackets too are sometimes necessary.
So be careful not to use = A1 + B1 / 2 if you really mean = (A1 + B1) / 2.
Press <Ctrl><~> to display the formulas / functions instead of their results in a worksheet.
Use cell references instead of constants in calculations wherever possible.
The Page Setup dialog box can be used to make various settings before you print.

13. Test and improve your knowledge and skills
Tips and Recommendation
Consider how you would do the calculation with ordinary numbers / then decide on formula
Order of operations in a calculation is important..
So be careful not to use = A1 + B1 / 2 if you really mean = (A1 + B1) / 2.
<Ctrl><~> to display the formulas / functions instead of their results in a worksheet.
Use cell references instead of constants in calculations.
The Page Setup dialog box can be used to make various settings before you print.

14. Test and improve your knowledge and skills
Important terms and concepts
Gridlines
Formula
Constant
^ (caret)