Which One Doesn’t Belong? (WODB) is a website with a very simple concept. It is “dedicated to providing thought-provoking puzzles for math teachers and students alike”. Basically, it presents four of something and you have to come up with a reason why each one of the four things doesn’t belong. But it is far more than a collection of brain teasers.

One way we can help students develop different ways of thinking in math is to have them work on activities where they have to classify mathematical objects. Continue reading Learning through classification: What makes this number (or shape or graph) different from the others? →