Perimeter – Year 3 maths lesson
UK version. UK school years, UK spelling and pounds (£). · US Math Department
A complete 45-minute lesson for Year 3 (ages 7–8) that runs on this page – at school or at home. Every answer is marked straight away, with a worked explanation.
- Time
- 45 minutes + 15 min homework
- Year
- Year 3 (ages 7–8)
- You need
- Paper, a pencil and this page
- Marked
- Instantly, with explanations
For parents: how to use this lesson
You don't need to know this topic yourself. The lesson explains each step on screen, the way Mr Euclid, our Head of Maths, likes it: one tidy step at a time. Every answer is marked straight away with a worked explanation, so you never have to mark anything.
- Read what your child will learn together.
- Press Start the lesson below and sit with your child for the teaching and the worked examples (about 19 minutes).
- Let them do the practice on their own. They choose Getting started, On track or Challenge – start on On track and move up after a few right in a row.
- Finish with the exit ticket and the talk question: “What is the difference between perimeter and area?”
- Later that day or the next day: the homework (15 minutes), then a practice test.
Watch out for
- Adding only the two sides that are labelled. Trace round the shape with a finger, saying each side.
- Multiplying the sides (finding the area). Perimeter is a length, so the answer is in cm or m, not cm².
Miss Hypatia's tip for home: Measure round a room, the garden or a photo frame.
What your child will learn
We are learning to find the perimeter of shapes.
Success looks like
- I can add all the sides.
- I can use 2 × (length + width) for a rectangle.
- I can find missing sides of an L-shape.
Key words
- perimeter
- the distance around the edge
- side
- one straight edge of a shape
- rectilinear
- a shape with all right angles
- centimetre / metre
- units for length
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Measure the perimeter of real objects (a book, a table, a mat) with a ruler or tape measure. No rulers? Use string to go round the edge, then measure the string.
The lesson, step by step
| Part | Time | How it is checked |
|---|---|---|
| Starter: quick recall | 5 min | Marked by Classfern |
| Teaching input | 10 min | Not assessed, self-checked |
| Worked examples and guided practice | 9 min | Not assessed, marked by Classfern |
| Independent practice | 15 min | Marked by Classfern |
| Plenary and exit ticket | 6 min | Marked by Classfern, self-checked |
Starter, "your turn", practice and exit ticket are marked by Classfern. Worked examples and teaching are not assessed. The hands-on task and the reflection are self-assessed. Explanations in talk are judged by the parent and not recorded.
The lesson
It runs here on the page. No sign-up and no names – progress is kept only in this browser.
Homework and practice at home
15 minutes: 8 practice questions, 3 multiple-choice questions and 2 to remember from earlier work, then a short reflection. New questions every time, all marked instantly.
More practice
More Year 3 maths lessons
Curriculum
National Curriculum for England, Year 3: “measure the perimeter of simple 2-D shapes”
Contains public sector information licensed under the Open Government Licence v3.0.
Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.