A 1-2 lesson pupil activity helping pupils to develop skills in producing a costing spreadsheet and working out break-even points for new products. Originally developed for Higher Level IB Design Technology Topic 10 (Commercial Production), but ideal to also be used in both Business and Economic at GCSE and IB level. Can be run as individual activity, but works best in pairs or small groups. Pupils are tasked with creating a lemonade stand business and given defined parameters of ingredients, tools and timescales to simulate both Fixed and Variable costs. They are encouraged to find the best prices possible for each and proceed to work out a suitable sales cost, based on break-even calculations. A teacher PowerPoint is included to guide the lesson, with extension tasks and variables to guide pupil understanding about fluctuating business costs and restrictions. Also included is a completed Excel spreadsheet with all necessary formulas and break-even chart which automatically updates when starting figures are changed.