Cartoons are a great way to use humour to teach and develop mathematical ideas. This Mathematicians Food Fight by cartoonist Daniel Reynolds is a good example. It plays with the idea that the mathematical symbol pi is an actual pie that can be used in a food fight. Very silly but very effective. What a great way to start a whole unit talking about and exploring the wonderful relationship between the circumference of every circle and its diameter. Perhaps your students can create their own maths cartoons to inspire students in another class too.