Goal: name and create a triangle with three straight sides and corners across size and orientation. Proposed code: AC9MFSP01. Prepare: two dissimilar triangle cards, three large strips, Card 102.
- Retrieve · 3 min. Child finds one straight-edge card and gives a visible reason.
- Model · 4 min. Count a triangle's three straight sides and three meeting corners, then turn it without adding a side.
- Guide · 5 min. Compare a small rotated triangle and large upright triangle; children trace and count each, not the space it occupies.
- Independent make · 7 min. Child connects three large strips end-to-end to make a closed triangle or directs a digital/adult placement; explain why an open three-strip path is not yet the outline.
- Test · 4 min. Rotate the made triangle and compare with a four-sided card. Ask which exact feature separates them.
- Exit · 2 min. “How many straight sides did you check?” Expect three; reteach closed shape versus open path if needed.