2. Terminology Recap
A worksheet
Columns
(letters)
Text labels
Numeric
data
Each cell has a
Text labels unique cell
Rows Column D reference e.g. D13
(numbers) Row 13
3. What is a model?
O (In ICT terms!)
O Tool that enables you to put different data
into a system and look at the outcomes it
produces
O Tool you can use to ask ‘what if…’
questions by changing variable or
formulae
4. Why use a spreadsheet?
O Speed
O Accuracy
O Automatic calculations
O Data can be changed easily
6. So what else will we be
learning?
O To use a spread sheet to generate models
O To ask questions of the models in order to
analyse and present data
O To use techniques to generate more
effective models
O To understand the relationship between
input and output values in a model
O To discuss other types of modelling that
can be used to simulate different events.
11. Homework
O Next lesson you will need to create your
own model based on mobile telephones
O The model will help answer the question
‘what is the best value phone for me?’
O What you have to do is to collect
information on the cost of running two
types of mobile phones and identify the
similarities and differences between the
packages.
Editor's Notes
Cell, row, columnLabel, numeric data, formulaDrag, copy, pasteFill handle,Sort,WorksheetChart, chard wizard(whilst asking the children questions make sure to differentiate the questions and give clues to help the lower ability)
Ask the pupils to explain what they understand a model to be if necessary prompt the children by saying that ‘ a model is a tool that enables you to put different data into the system and look at the outcomes this produces’ ‘ a model is a tool you can use to ask (What if.....?) questions by changing the variables or formulae’
Explain the objective for this lesson.
Should look like the image aboveOn the large display and point out the cells containing money coming in, thecosts to the organisers, the estimated number of people coming to the fete andthe cell with the formula that calculates the overall profit or loss.As you indicate the different cells in the model, check pupils’ understanding of thespreadsheet functions by asking selected pupils to say whether cells containnumeric data, labels or formulae.Ask pupils to identify which cells contain variables – numeric data that can bechanged to different values. Check that pupils understand what is meant byincome, expenditure, profit and loss.
Distribute 8.4P1d School fete worksheet.doc. Say that this contains questionsabout how the model works and how it can be interrogated by changing thevariables and asking ‘What if…?‘ questions.Demonstrate how changing a variable will cause other values in the model to berecalculated, by changing the number of people who are expected to attend. Pointout that the model now gives different figures for income and profit. Ask pupils towork in pairs to complete the worksheet. Say that at the end of the lesson you willask them about the effectiveness of this model and, as they work, they shouldthink about this.As pupils work, circulate to assess their understanding. Ask these questions.• Which cells contain data, labels or formulae?• Which cells are dependent on other cells?• Which variables can be changed in the model? What does this tell us?• What other questions could we ask?For differentiation make sure you vary the questions for particular pupils. Once they have completed the work sheet get them to peer assess their work by using the 8.4T1e School fete worksheet answers.doc Bring the class back together to check and discuss answers to the worksheet. Askselected pupils to explain their ‘What if…?‘ questions and to describe how theychanged the model to find the answer. Demonstrate on the large display as eachpupil explains the procedure. Ask other pupils to check if this is correct. Prompt forfurther explanation if the procedure is not clear.Ask pupils what they thought about the trial-and-improvement method for findingthe break-even number of people. If necessary, prompt them by saying:• it can be slow getting to the answer;• it can be tedious;• it can be difficult to find a starting point.Ask pupils to reflect on the processes which the spreadsheet is carrying out
Distribute 8.4P1f Goal seek.doc. Ask pupils to think about the question. Ask apupil to explain which cells will need to be changed. Ask another pupil to explainhow to use the Goal Seek… function. Demonstrate on the large screen. Tell pupilsto work in pairs, using the Goal Seek… function to complete the other questions.To differentiate the class pair up pupils with similar levels or make small groups for the lower ability.You could also Provide handouts of 8.4T1g Goal seek helpsheet.doc. If they are really struggling
Ask pupils to consider what makes a good model. Possible answers may includethat it:• is easy to use;• is accurate;• simulates a real situation;• simulates a real situation which answers some questions.Also ask pupils to reflect on the school fete model they have been using. Ask thesequestions.• Do you think the school fete model is a good model?• How accurate is it?• How could we find out?• How could it be improved?Draw out the following points.• The accuracy could be checked by trying out the model with test data.• It would be easy to add new variables, for example, to calculate income andpurchases.• The rules of the model could be extended to take account of other factors suchas weather, advertising and past enjoyment.• The model is limited because it is assumed that people will spend equalamounts or undertake the same activities.• The accuracy could be checked by comparing the model with a real schoolfete.
Before they go just gather some factors which they will need to take into account when choosing a mobile phone, next lesson they will be looking at specifically at the cost of running a mobile phone.
