Introduction

A school wants to email every pupil who takes Maths or Science, but not send the same message twice to someone who takes both.

That is a set problem: two groups, an overlap, and a clear list of who is in which group. Later, when a mark calculator turns a raw score into a grade the same way every time, that is a function.

Sets organise collections. Functions apply a reliable rule from input to output.

You will learn set notation, Venn diagrams, union and intersection, then functions: domain, range, evaluating, composites, inverses, and graphs.