Applying Pythagoras' theorem 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: Grid paper or squared paper; Ruler and pencil. 1. Say the goal of Applying Pythagoras' theorem in plain words once. 2. Adult marks a 3-4-5 right triangle and checks 3²+4²=5². 3. Child builds three right triangles on grid paper and checks a²+b² against c². 4. Fresh check: one fresh 3-4-5 (or similar) check. Record and stop. Done: three checked right triangles with a²+b² and c² recorded. Proof: parent note of examples and results. Stop: End after the fresh check; keep optional challenge for another day.