Curated OER
Unit Squares and Triangles
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle and angle...
Illustrative Mathematics
Weather Graph Data
Teaching young mathematicians about collecting and analyzing data allows for a variety of fun and engaging activities. Here, children observe the weather every day for a month, recording their observations in the form of a bar graph....
Science Matters
Oh Heron
Two teams—the environmentalists and herons—play four rounds of the game, Oh Heron. Using hand symbols to represent food, shelter, and water, players locate their match to produce more herons while those unmatched decompose.
Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Curated OER
Triangles Inscribed in a Circle
Are you tired of answers without understanding? Learners can give a correct response, but do they really understand the concept? Have young mathematicians think deeper about linear functions, angles, and formulas in algebra. Learners are...