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

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

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()

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

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