Topic 10- Spreadsheets

Topic 10- Spreadsheets

1. A spreadsheet application such as Excel can store all its data in a single file (with an .xls extension). This file is called a 'workbook'.

   • A workbook is made up of one or more 'worksheets'. A worksheet is a single tab in the spreadsheet workbook

2. Cells

   • □ A cell reference always starts with a letter and ends with a number e.g. A5 or H28
   • □ A range of cells is a set of cells in a row or column
   • □ Data entered into cells can be different data types e.g. text, number, currency, date, percentage etc.
   • □ Each cell can contain:
     •  Data – any values (text or numbers) that are entered for the use of calculation
     •  Formulas and functions – mathematical calculations carried out automatically
     •  Labels – any text in a cell describing the data in a row or column(titles, headings that identify data)

3. Formulas

   • □ Formulas perform calculations on cell contents.
   • □ Formulas appear in the formula bar.
   • □ The result of a formula is automatically recalculated every time the data on a spreadsheet changes.
     •  Below are the 4 main mathematical operations:  + Add  - Subtract  * Multiply  / Divide
     • =(B3*C6)+E12
   • □ Must start with an =

4. Functions

   • □ Functions are part of spreadsheet software. They are specialised calculations built in to the spreadsheet software.
   • □ Must also start with an =
   • □ Function name describes what a function can do SUM, COUNT, AVERAGE, MIN, MAX, IF
     • =SUM(D2:F7)

5. Formatting

   • □ Cells are often formatted to reflect the data that is held in them. Data types include:
     • □ Currency, number, real, integer (whole number), date, text
   • □ The content of a cell can be formatted:
     • □ Font style, size, colour, border style, alignment, cell colour.
     • □ Multiple cells can be merged in to one cell

6. Replicating cells

   • □ When you position the mouse pointer in the bottom right hand corner of the cell and drag down or across the spreadsheet tries to respond intelligently. If there is a formula in the cell, the spreadsheet tries to adjust it as it goes down the page to fit in with the new position and the cells being referred to.

7. Graphs&Charts

   • □ Using charts/graphs allows us to notice patterns & trends more easily
   • □ Specific data can be selected on a spreadsheet and a chart/graph of this data can be created.
     •  Bar charts – to compare values  Pie charts – to show how a total is divided among a number of different categories.  Line graph – display trends

8. Cell Referencing

   • Relative Cell References
     • □ If a formula is copied by filling down, the cell references are adjusted as you drag the replication pointer down the page. This is because it uses the relative address of the cells based on their position in the worksheet.
     • Relative cell references is when a cell is used in a formula and the formula is copied to a new cell reference (address) , the cell references (cell address) changes to take account of the formula’s new position.
   • □ When a formula is copied by ‘filling down’ the cell references in cells are adjusted as you drag the pointer down the page.
   • Absolute Cell References
     • □ Some we need to use part of a formula that does not change. For example is VAT was recorded in B2 as 20% then the B2 part of the formula must not change because the rate will be 20% for everything. All the other cell ranges will change. When the formula is copied down, the relative address changes but the absolute doesn’t.
     • □ These use the $ character in front of the letter and number that are required to stay the same. Think of it as the $ as glue. It glues the absolute cell into every formula it is needed in.
     • Absolute cell referencing is where a reference to a cell used in a formula where, when the formula is copied to a new cell reference (cell address), the cell reference (cell address) does not change. It is glued in place by the $ character.

9. 'What if?' Calculations

   • □ Changing the data in a spreadsheet model allows you to make and test predictions. You may explore what would happen to your profit if VAT changed to 30%. These are known as what if calculations. They allow you to use a spreadsheet to see what would happen if certain figures changed in a spreadsheet.

10. Benefits

    • Accurate calculations
    • Formulas can reused and stored
    • What if calculations
    • Calculations involving large numbers are possible
    • Graphs/Charts
    • Replication
    • Automatic recalculation