Missing angles – Year 6 maths lesson
UK version. UK school years, UK spelling and pounds (£). · US Math Department
A complete 45-minute lesson for Year 6 (ages 10–11) that runs on this page – at school or at home. Every answer is marked straight away, with a worked explanation.
- Time
- 45 minutes + 20 min homework
- Year
- Year 6 (ages 10–11)
- 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: “Why do the angles on a straight line add up to 180°?”
- Later that day or the next day: the homework (20 minutes), then a practice test.
Watch out for
- Using 360° for a straight line (or 180° for a point). Show it with a paper circle: fold it in half to see 180°.
- Adding the known angle instead of subtracting it. Ask: what is the total, and how much is still missing?
Miss Hypatia's tip for home: Find right angles, straight lines and turns around the house; open a door to different angles.
What your child will learn
We are learning to find missing angles.
Success looks like
- I know the totals: 90°, 180° and 360°.
- I can find a missing angle by subtracting.
- I can check my answer adds up to the total.
Key words
- degree (°)
- the unit for measuring turn
- right angle
- 90°, a quarter turn
- acute / obtuse / reflex
- less than 90° / between 90° and 180° / more than 180°
- angles on a straight line
- add up to 180°
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Tear the three corners off a paper triangle and put them together on a straight line to see that they make 180°.
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
20 minutes: 10 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 6 maths lessons
Curriculum
National Curriculum for England, Year 6: “recognise angles where they meet at a point, are on a straight line, or are vertically opposite, and find missing angles”
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.