Fun Math Kids

Smart Starters · Ages 8 to 10

All Smart Starters games

Angle Detective Grid

Solve angle clues on an evidence grid at a detective agency, placing the right number of degrees to crack each case, for ages 8 to 10.

PuzzleAngle recognition and types~6 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 Angle Detective Grid

Angle Detective Grid turns angle recognition into casework at a mystery detective agency. Each cell on the evidence board holds an angle clue, and the young detective works out the missing number of degrees and places it to unlock the next lead, learning right, straight, and full-turn facts along the way. It is built for ages 8 to 10 (grade 4 and grade 5) with clear instructions, large touch targets, and gentle pacing, so children can play independently or alongside a parent. Correct answers bring encouraging sounds and a small celebration, while mistakes are never punished and simply invite another try, which keeps confidence high. Difficulty grows step by step so the challenge always matches the child, supporting steady, progressive learning across the upper-primary 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 Smart Starters 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 90 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, angles, reasoningAligned to geometry, angles, reasoning number and operations objectives.
  • United KingdomNational Curriculum for England — Maths · geometry, angles, reasoningAligned to geometry, angles, reasoning number and operations objectives.
  • AustraliaAustralian Curriculum v9.0 — Mathematics · geometry, angles, reasoningAligned to geometry, angles, reasoning number and operations objectives.
  • CanadaPan-Canadian Provincial Standards · geometry, angles, reasoningAligned to geometry, angles, reasoning number and operations objectives.
❓ FAQ

Frequently Asked Questions

  • It is designed for children aged 8 to 10 (grade 4 and grade 5) and follows the upper-primary maths curriculum.

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