Picture a gaggle of maths geeks enjoying a nice drink of pop in a pub on the banks of the Avon in Stratford.
How long do you think it took for the talk to turn to maths?
Well, when @just_maths whipped out her iPhone and showed us Area Maze, we were all immediately engrossed.
This type of puzzle on involves whole numbers and needs logical and proportional reasoning to solve.
Of course, I immediately downloaded it when I got home, and had a play. Not only did I enjoy playing it, I could see how this type of puzzle could be used in my lessons.
Whilst searching for the app, I saw other similar ones on iTunes.
Area Quiz? from Wasabi Applications has a more refined and less "raw" style, and even offers problems with triangles as well as the original rectangles.
I like both of these apps, but I must say that I prefer the second type. The interface allows you to annotate over the top of the diagrams, which I have found extremely useful.
Have a look for yourself: and have fun, knowing that you mind is being stretched and challenged.