Fiducia TogetherRearranging formulae
Changing the subject of a formula so a different letter is on its 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
Rearranging makes another variable the subject: turning v = u + at into a = (v − u)/t.
Where it applies
Both tiers, and constantly in physics.
How it works
Do the same thing to both sides, undoing operations in reverse order.
Where the wanted variable appears twice, collect those terms on one side and factorise.
How to use it in your work
Write each step. Method marks exist here and a wrong final answer with correct working still scores.
In physics, rearranging BEFORE substituting numbers is far less error-prone than the other way round.
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.