Fun Math Kids

Logic Masters · Ages 11 to 12

All Logic Masters games

Circle Geometry Builder

Apply circle theorems to find missing angles in a celestial observatory, for ages 11 to 12.

BuilderCircle theorems and angle relationships~7 min per level4 levelsAll devices
  • Free · no account required
  • COPPA compliant
  • +10 XP per level
  • 4 levels
  • Plays on all devices
  • Curriculum-aligned

The learning journey

Every activity is one step. Here is where this one fits.

  1. Play(you are here)Learn the idea in a game
  2. PractiseLock it in on paper
  3. ReviewCome back and keep it sharp
  4. MasterTake on a harder challenge
  5. AchieveEarn a certificate

About Circle Geometry Builder

Circle Geometry Builder sets students in a celestial observatory, where orbital diagrams hide missing angles. Learners read each circle-theorem diagram, recall the relationship between angles at the centre and circumference, and choose the missing angle, deepening their geometric reasoning with every cosmic puzzle. It is built for ages 11 to 12 (grade 6 and grade 7) with clear instructions, large touch targets, and progressive difficulty, so students can work independently or alongside a parent. Correct answers bring encouraging feedback and a small celebration, while mistakes are never punished and simply invite another try, which keeps confidence high. The challenge grows step by step so it always matches the learner, supporting steady progress across the lower-secondary curriculum used in the US, UK, Canada, and Australia. The game runs in any modern browser with no app to install, no sign-up, and no advertising shown to children. Progress is saved only on the device and appears in the Parent Dashboard, so families can follow growth without any data leaving the browser. It pairs well with our Logic Masters worksheets for offline practice of the same skills.

Chosen by the skills this activity practises.

A hand for grown-ups

Before you start
Point out a few shapes in the room first. Geometry starts with noticing, and it is everywhere.
While they work
Encourage them to turn shapes around and look from different angles — literally, with a real object if there is one.
Afterwards
Go on a shape hunt around the house together. Naming real shapes cements the vocabulary.
Watch out for
Thinking a rotated square is a "diamond", or that size changes what a shape is. Turning a real cut-out shows it is the same shape.
Away from the screen
Spot shapes on a walk, build with blocks, fold paper into shapes. Talk about corners and sides.

How to play

  1. A question appears on screen

    A maths question is shown in large text at the centre of the play area. A timer bar begins counting down from 100 seconds.

  2. Choose the correct answer

    Answer options are shown as large buttons. Tap and drag, or use the mouse on desktop. Any input method works — touch, mouse or keyboard.

  3. Build your streak

    Each consecutive correct answer increases your streak. A longer streak lights up the flame icon and adds a bonus multiplier to the XP you earn for the level.

  4. Finish the level

    Each level has 4 questions. Complete them to earn the full level reward (+10 XP, plus up to +10 XP for a perfect run). Progress is saved locally and shown on the Parent Dashboard.

🎓 Curriculum

Curriculum alignment

Mapped to national curriculum frameworks so teachers and parents can match practice to school standards.

  • United StatesCommon Core State Standards for Mathematics · geometry, circle-theorems, anglesAligned to geometry, circle-theorems, angles number and operations objectives.
  • United KingdomNational Curriculum for England — Maths · geometry, circle-theorems, anglesAligned to geometry, circle-theorems, angles number and operations objectives.
  • AustraliaAustralian Curriculum v9.0 — Mathematics · geometry, circle-theorems, anglesAligned to geometry, circle-theorems, angles number and operations objectives.
  • CanadaPan-Canadian Provincial Standards · geometry, circle-theorems, anglesAligned to geometry, circle-theorems, angles number and operations objectives.
❓ FAQ

Frequently Asked Questions

  • It is designed for ages 11 to 12 (grade 6 and grade 7) and follows the lower-secondary curriculum.

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