When I was about 12 I had a maths lesson on Friday afternoons at school. Towards the end of term, I remember my teacher dumping a pile of holiday brochures on his desk and setting the class the task of planning and costing up a holiday. This was pre-Internet, so brochures and travel agents were how you did it back then.

Location, flights, hotel, meals, activities, excursions, hire cars, spending money etc all had to be considered for a family of three on a fixed budget. I remember that the submitted work was never actually marked since there was no "correct" answer, and the reasoning behind it was essentially to get experience of planning and budgeting. A great application of numeracy skills for a real-world task.

These days simplified versions of that exercise are relatively common for teachers to give to pupils but as we discovered the following term, what we were actually doing was literally planning his summer holiday with his family because he couldn't be arsed. He'd crowd-sourced his research.

Absolute genius of the man.