Lesson Sketch: Solving problems graphically

Here is a pic I recently used in class, which was taken from an idea by Dan Meyer:

The question of course being "Have I scored?"
I had four different pictures. We went through one together on the board. We tested our calculations by watching the full video. Each pupil then tackled a random choice of the others. Difficulties as always arose trying to be anywhere near accurate on the interactive whiteboard, but aside from that the pupils seemed very engaged and eager to contribute in the lesson. Admittedly that isn't too difficult with the pupils in this school, but what I really enjoyed was the way some of them seemed so shocked, firstly that an equation could actually be used for something, and secondly that it worked.
One touch I like about the image is that you don't need any extra props to establish scale.

Notes for improvement:

• I think I rushed through the early example, afraid that they wouldn't get it or would lose interest without my support. I needn't have worried as the pupils rose to the challenge very quickly and a little more patience on my part would have encouraged pupils to test ideas out with each other and come to an answer independently of me.
•  On the pictures the pupils worked on themselves, most of the kids were about 5 mins from having their answer when the bell rang. I panicked and showed them the videos revealing the answers anyway. Doing it again I would probably allow two lessons for the topic and would just take my time. I guess I'm still getting used to these 35 min lessons.