Spreadsheets

Introduction

What is a spreadsheet?

• A spreadsheet program is used to manipulate numbers

• One of the most popular spreadsheet programs is Microsoft Excel

What is in a spreadsheet?

• A spreadsheet is made up of • Cells• Rows• Columns

• A spreadsheet look like this -

Cell A1

Cell E7

Column D

Row 8

Formula line

Cell contents

Each cell can contain• A number (a value)• Text• A formula

Formula

In Excel a formula always starts with =

A formula can be • simple• complex• conditional

Examples of formula

Simple: =D1+C1

Complex: = LEFT(D5,7,2)

Conditional: =IF(D5>=50,”pass”,”fail”)

Functions

A function is an inbuilt formula.eg

=SUM(B5:B10)=AVERAGE(B5:B10)=MAXIMUM(B5:B10)=MINIMUM(B5:B10)

Formatting• To change how something looks,

we change it’s format• We can change the look of

• the cell itself• border, background colour

• the attributes of the cell• number of decimal places, currency

• We can change• the column width• the row height

Insert column/rowIf we need to add data to a particular part of the spreadsheet, we can insert a column or a row.Once the column or row is inserted, we need to add the data.When a column or row is inserted, the formulae are automatically updated.

CalculationCalculation can be

•automatic•manual

Automatic recalculation means that all the formulae in a spreadsheet are recalculated every time a change is made to the spreadsheet.

Manual CalculationManual recalculation means that the formulae in a spreadsheet are only recalculated when the user presses a certain key.

This feature is used when the user is typing in a large amount of data. Automatically recalculating the formulae after every entry would make the data entry very much slower.

Cell protectionCell protection is used to prevent the user from changing the contents of a cell (it locks the cell).

In a spreadsheet, the column and row headings and the formulae are usually protected.

Example of cell protection

Protected cells

ReplicationReplication is used to make a copy of a formula.

Theer are two types of replication:

• relative• absolute

Relative ReplicationWhen we copy the formula down a column, the cell references change to be appropriate for that row. C3 changes to

C4 changes to

C5 changes to

C6

Absolute ReplicationWhen we copy the formula down a column, the cell reference does not change.

It stays absolutely the same

Example of Absolute Replication

C5 changes to

C6 changes to

C7 changes to

C8

B1 does not change

In Excel, the $ sign before a letter or number in the cell reference means that it does not change when replicated.

ChartingThe data in a spreadsheet can easily be shown as a chart.

A graph or chart is used to present facts in visual form. It should be used to make facts clearer and more understandable

It is easier to spot a trend or pattern in a chart than in a table of numbers.

Example of charting

Example of a trend

Spreadsheets

End of presentation