1. Spreadsheets In today’s lesson we will look at:
The parts of a spreadsheet
How and why we use a formula to perform a calculation
What we mean by modelling

2. The Parts of a Spreadsheet
A spreadsheet is made up of cells
Cells form rows and columns
Cells have a name, called a reference – this is made up of the letter at the top of the column followed by the number of the row, e.g. A1 or D4
A group of cells is called a range

3. Formulae A formula always begins with an = sign
Formulae use cell references wherever possible – if you plan to copy a formula you can fix the reference with $ signs
A simple formulae just has the = sign, cell references and +, -, * or /
A function is a formula with words in it, e.g. =sum() or =average()

4. Why Use Formulae? A formula can be replicated – copied to other cells
Formulae have some of the benefits of using a calculator – it is quick and easy to find an accurate answer
The main benefit is that your answers will still be correct if you change other values on the spreadsheet – you can create a model and make predictions

5. What is a Model?
A model is a representation of a real-life situation using a computer
Models are made up of rules and variables and can be used to make predictions
A variable is something in the model that can be changed
The rules tell us how the variables are linked together, and can be created using formulae