We play this game A LOT in preschool because categorizing items is extremely important. It helps children to begin to group their thoughts together, begin to recognize similarities/differences and ultimately helps children solve problems. The WHY gives children the opportunity to explain their thinking. A child might not come up with the same answer as you or the one you are looking for and that is okay. As long as they can justify and explain why they sorted it that way and it makes sense it can be correct! And another great thing about this game is the language the child will use while explaining their thinking and reasoning. There is so so so much learning and critical thinking happening here.
You can do this with a variety of different materials you have at home. I am showing you examples of how I grouped items (swipe) and circled the item that I would say doesn’t belong. You will want to adapt this depending on your child’s ability. For younger kids you may want to start with things that all look the same and one that looks different. I did this for Max (6) so I made it harder and he did great with it! Just make sure to always ask the question, What doesn’t it belong and Why?