It is a great exercise in maths - the boys have to add up their expenses, work out prices, add and subtract on their feet all day, pay stall fees and calculate their net profit at the markets conclusion.
It is also great for their confidence and communication skills as they are interacting with customers, practicing their salesmanship (is that a word??) and ultimately feeling the satisfaction of a wad of self made cash in their back pocket.
They are building strong stamina - I really only worked the stall when they had a toilet break, and they even made a few new friends during the course of the day.
And now, to save or to spend? That seems to be the question.....