Changing the subject with simple formula
I can apply an understanding of inverse operations to a simple formula in order to make a specific variable the subject.
Changing the subject with simple formula
I can apply an understanding of inverse operations to a simple formula in order to make a specific variable the subject.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Changing the subject can be thought of as solving an equation in one unknown.
- Throughout the rearrangement, the expressions on each side of the equals sign remain equal.
- Changing the subject can offer different perspectives on the relationship.
- It can make it easier to calculate the unknown value if that is the subject.
Keywords
Formula - A formula is a rule linking sets of physical variables in context. The plural of formula is formulae.
Subject - The subject of an equation/a formula is a variable that is expressed in terms of other variables. It should have an exponent of 1 and a coefficient of 1.
Common misconception
The subject of a formula is just the first term in the formula.
Draw attention to the variety of equations and formulae used in the lesson.
To help you plan your year 9 maths lesson on: Changing the subject with simple formula, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 9 maths lesson on: Changing the subject with simple formula, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 maths lessons from the Expressions and formulae unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions
Exit quiz
6 Questions
$$c + d + e = f$$ -
$$f$$
$$c = f-(d+e)$$ -
$$c$$
$$c-d-f=e$$ -
$$e$$
$$d=c-ef$$ -
$$d$$