Fiducia TogetherVenn diagrams and sets
Overlapping circles showing what belongs to which group, with a notation of their own.
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.
What it is
A Venn diagram shows sets as regions. The notation: ∪ is union (in either), ∩ is intersection (in both), ′ is the complement (not in), and ξ is the universal set.
Where it applies
Both tiers, more heavily at Higher where it is tied to probability.
How it works
Fill the intersection FIRST, then work outwards subtracting what is already placed. Filling the outer regions first is the standard route to double-counting.
How to use it in your work
Read the notation carefully — (A ∪ B)′ and A′ ∩ B′ are the same region, and A′ ∪ B′ is not.
Check your numbers total the universal set before answering.
Where to get help
Your teacher, your board's specification for what is on your paper, and Bitesize for worked examples. The maths song runs the topics in order.
Revise this with a song
These are ours. We write revision songs because a lot of people remember a tune when they cannot remember a page, and because revising out loud in the kitchen beats staring at a highlighter.
- The Maths Song The GCSE maths topics, in order.
Where to read more
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.