For the "Carbon Footprint Tracker" scenario, our 14-year-old students use the FOSSBot as a personal calculator to quantify CO2 emissions. The activity uses specific emission factors, such as 0.19 kg CO2 / km for car travel and 0.00 kg CO2 / km for cycling. When teaching the algorithmic thinking exercises and variable manipulation (total, activity, qty, factor), do you let students create their own menu-driven interfaces, or do you provide a template to save time?