Before starting the modelling spreadsheet it is important that pupils understand the financial terms that they will use.

Show the presentation4a - financial terms, there are notes4a and handout4 to accompany it.

Develop this activity by asking:

• Where have you heard of these terms being used before?
• Why does a business need to know the break-even point?

Show pupils the language cards language4 for this lesson.

This part of the activity is important as it shows pupils how to use a spreadsheet to model material costs and then to use this information for analysing break-even points.

Show pupils the example4b of Troy's Toys. This workbook contains 3 sheets. The first gives instructions on how to use the spreadsheet. The next one requires pupils to enter a maze length (assuming that all mazes are cut from 100mm materials), the number of mazes required and the number of ball bearing that each maze uses.

The next sheet then works out the various costs depending upon materials choice. The spreadsheet use ROUNDUP and ROUNDOWN functions. Pupils will learn about this in the next part of the activity.

Develop this by asking:

• Why are ball bearings offered in packets of different amount?
• Why is it important that Troy'sToys looked at different materials?

Distribute the worksheet4b - this explains the spreadsheet and asks pupils to carry out certain tasks.

During this section pupils may wish to compare ideas for the spreadsheet, perhaps using criteria. Explain that using criteria can help select answers that are 'fit for purpose'

Pupils are now asked to plan a similar spreadsheet. During the next activity they will gather data to enter into it and then use it to financial model some mazes. (A sheet of prices for materials is available in Activity 5 both online and in printed form although pupils may wish to research their own prices)

Some pupils may benefit from using a partly prepared spreadsheet.

Using homework4 pupils are asked to prepare a slide for their final report that explains financial terms and how this relates to their business.

You may feel it appropriate to provide the homework sheet in electronic format for those pupils with computer access at home. Consideration should then be given to:

• How they would return the work and the style - electronic or printed.
• Virus protection.
• Authenticity of the work.