What does a line of reflection symmetry guarantee?
Folding a painted/blot butterfly: drip paint on one half of a paper, fold it, and the matching wings appear — same fold-and-match test the explainer runs. Seasonal: cutting a folded-paper snowflake or a paper heart for Valentine's, where one cut on the folded edge mirrors itself.
Talk about it
- Draw half a butterfly on a folded page, then guess: when we fold, will the wings match perfectly?
- Drip paint on one half, fold, and predict what the other half will look like before you peek.
- Find one thing on your face that isn't quite mirrored — why does symmetry let your brain skip looking?