Module 4.2: Calculations

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

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: 1 4 65 86 Built-in functions: SUM , AVERAGE, MIN

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

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.

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.

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)

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

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

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.

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 (‘#’).

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.

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.

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