Maths reasoning KS3 – Doughnuts lesson plan

What's included?


Key Stage



Years 7-9


This standalone maths reasoning KS3 lesson is based on the scenario of a teacher buying doughnuts for each student in their class (whether you wish to buy real doughnuts for your students is up to you!).

The doughnuts are all identical but come in two different-sized bags, which cost different amounts of money. What total numbers of doughnuts is it possible to buy and what is the cheapest way of getting at least a certain total number of doughnuts?

Maths reasoning KS3

Exploring these questions involves students in considering multiples and systematically examining various combinations of the bags. Justifying their findings requires and develops careful mathematical reasoning.

Some of the conclusions may be surprising, such as that it is sometimes cheaper to buy more doughnuts! Investigating when and why this happens provides a good challenge for students that helps them to use what they know and apply it to an unfamiliar context

Colin Foster is an Assistant Professor in mathematics education in the School of Education at the University of Nottingham. He has written many books and articles for mathematics teachers.

Browse more KS3 maths games and lesson ideas. We also have maths question worksheets for Year 7Year 8Year 9 and GCSE maths.

Maths reasoning KS3 lesson plan
Maths reasoning KS3 – Doughnuts lesson plan

You'll also receive regular updates from Teachwire with free lesson plans, great new teaching ideas, offers and more. (You can unsubscribe at any time.)

Which sectors are you interested in?

By signing up you agree to our Terms & Conditions and privacy policy

Explore teaching packs

Pie Corbett Ultimate KS2 Fiction Collection
Pie Corbett Ultimate KS2 Fiction Collection
Fire up KS2 pupils' imagination with this collection of 20+ fictional stories, written by literacy expert Pie Corbett. Each ... more
21 x resources
Pie Corbett KS2 Non-Fiction Collection
Use Pie Corbett’s non-fiction texts to inspire your KS2 pupils to get writing. Each resource contains an original text in ... more
6 x resources
Pie Corbett KS2 Poetry Collection
Inspire KS2 pupils to be creative and express themselves with this pack of Pie Corbett poetry. Each of these Pie Corbett Tal... more
7 x resources
WAGOLL classroom resources
WAGOLL Packs from Real Authors
Peer inside the mind of award-winning children's authors and help pupils understand how to create engaging characters, capti... more
10 x resources
Art KS2 inspiring medium term plans
Art KS2 Inspiring Medium Term Plans
Get pupils' creative juices flowing with these expert medium-term art plans for KS2. Each resource consists of a full half-t... more
6 x resources
Magical Harry Potter Teaching Ideas
Magical Harry Potter Teaching Ideas
Spark pupils' imaginations with these inventive and exciting teaching ideas, all themed around the wonderful world of Harry ... more
11 x resources