Which One Doesn’t Belong? is a site I learned about recently when looking for resources to promote Computational Thinking Skills amongst primary school children. This maths/problem solving site is for students of all ages and challenges them to look at a set of four images and determine which image doesn’t belong and then justify their answer. The best part of this site is that each problem has multiple correct responses that can be justified. Students have to think through the differences that they see and then make logical decisions and be able to explain it to others. This is an excellent activity for developing key skills of Computational Thinking, namely, Abstraction and Pattern Recognition. There are three different categories for Which One Doesn’t Belong including: Shapes, Numbers, Graphs and Equations.
This is a practical way of developing these skills in the classroom. My favourite part about this site is that there are multiple answers for each set. Students can see how perspective and the attributes that you are focussing on can change the answer. The site is a great catalyst for critical thinking and problem solving in maths (or any) class. Put a problem set up on a projector as a maths class starter and ask your students to independently choose their answer and be ready to justify it to others. Then, as a class, discuss answers. After students have done this once, challenge them to find as many possible answers as they can independently before sharing responses. This site would be a great tie-in with literacy to discuss perspective and vantage point. Children love the activity and it always generates great debate and discussion in both small group or whole class setting. Take the puzzle blow for example.
We could say that 9 doesn’t belong because it’s the only single digit number in the grid
We could say that 16 doesn’t belong because it’s the only even number in the grid
We could say that 43 doesn’t belong because it’s the only non square number in the grid
Can you think of a reason to justify why 25 doesn’t belong?
Children really love the shape category and there is always lively debate around justifying what item doesn’t belong.
Check out https://wodb.ca/ for lots more examples