Today, we're going to play some games to practice sorting things into groups. This is a really important skill called categorization.

Explain to your students that their brains are amazing at sorting—like putting all the LEGO pieces together or all the cars together. Today, we're going to use that skill to find the one that doesn't belong—the odd one out!

In coding, a computer needs to know exactly how to sort and group information. Finding the item that is different is a fundamental building block of all computer programs.

Introduce the game of Word Tennis as a fun, fast-paced way to warm up your brains and practice categorization. Explain that in this game, students must quickly think of items that belong in the same group.

Choose two students to come to the front and face off. Start with a simple category, such as "fruits." Students take turns naming a fruit (e.g., apple, banana, orange) until one of them either repeats an item or can't think of another one that belongs in the category. The student who can't think of an item is "out" for the round.

Play a few quick rounds, inviting new students to the front and using different categories (e.g., farm animals, things that are red, clothes we wear). This gets the entire class actively thinking about what items belong together in a specific group.

Display the "What Doesn't Belong" Slideshow on your Interactive Whiteboard.

Explain to the class that each slide shows a group of items, and their job is to find the odd one out—the item that is different from all the rest.

For each slide, ask the students two questions:

1. "Which item is the outlier (the one that doesn't belong)?"

2. More importantly: "Can you explain why it doesn't belong?"

Encourage them to name the category or the "rule" that the other items follow (e.g., "The category is 'Things you can eat,' and the shoe doesn't belong."). This skill of identifying the rule and the exception is fundamental to finding errors in computer code.

Well done! Now, gather the class and explain that their work today in finding the "odd one out" is actually a fundamental concept used by computer programmers every single day.

Every time they made a group, they were using categorization. Every time they identified the one item that didn't belong, they were spotting an outlier.

This skill is vital in computer science because:

• Data Sorting: Computers use categorization to sort millions of pieces of data—like organizing photos, emails, or files on a website.

• Debugging: When a program has a bug, the programmer must look through lines of code to find the outlier—the one instruction that doesn't belong—to fix the entire program.

By mastering how to spot what doesn't belong, your students have practised a core logical skill that is essential to building and fixing technology!