National Security Agency
Classifying Triangles
Building on young mathematicians' prior knowledge of three-sided shapes, this lesson series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy...
Curated OER
Math: Geometric Fun and Games
Third graders discover geometric shapes by completing a series of games and activities. Using ropes with knots tied every foot, they make shapes such as squares, triangles, and hexagons. In pairs, 3rd graders use pattern blocks to...