Measuring angles (age 9+)
Recognise angle measure as additive; find unknown angles by adding or subtracting on a diagram using equations with a symbol for the unknown
Lesson
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“Measuring angles (age 9+) means practising the idea at the table with counters or paper models and one clear check. We will demo once, then your child tries.”
Bring to the table
- 20 counters
- Paper and pencil
Extra for the adult
Worked example. Start with 12 counters, remove 4, 8 remain. Write 12 − 4 = 8.
Optional challenge. For Measuring angles (age 9+), add one harder example after success.
What to notice. Keep one parent note: examples tried; results; support used. This session samples Measuring angles (age 9+), not mastery.
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1 approach
Measuring angles (age 9+) means practising the idea at the table with counters or paper models and one clear check. We will demo once, then your child tries.
Materials: 20 counters; Paper and pencil. Adult models 12 − 4 by removing counters, then writes the difference. Child solves three subtraction problems with counters and records each difference. Done: three correct differences with counters matching the writing. Stop after the fresh check; keep optional challenge for another day.
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Start practiceMeasuring angles (age 9+) practice
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Learning resources
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BBC Bitesize · Practice link — not the full lesson
KS3 Maths
Before you open · source notes
KS3 Maths supports Measuring angles (age 9+). An adult previews and guides; this is a learning page, not a scored quiz.
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Before you openAsk the learner one fact they learned and one question they still have.
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Source, access and review notes
Public BBC Bitesize page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.
BBC Bitesize. “KS3 Maths.” External page; Gakuva does not copy, host, embed, or redistribute materials.
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Check understanding
- Two angles on a straight line are 65° and x°; find x = 115°
- An angle is decomposed into 35° and 40°; state the whole angle is 75°
- Solve: angles at a point are 120°, 90°, and x°; find x = 150°
“If two angles sit next to each other on a straight line and one is 65°, can your child work out the other angle — knowing that angles on a straight line always add up to 180°?”
Curriculum record
- Type
- Procedural
- Subject
- Mathematics
- Domain
- Geometry
- Age range
- Ages 9–12
Standards