Illustrative Mathematics
What is a Trapezoid? (Part 2)
This collaborative activity investigates the meaning of a trapezoid and a parallelogram. It begins by presenting two different definitions of a trapezoid. Learners are to reason abstractly the difference between the two definitions and...
Illustrative Mathematics
A Midpoint Miracle
Young geometers develop one of the fundamental properties of quadrilaterals (connecting side midpoints gives a parallelogram) in this short but thought-provoking exercise. Using a combination of hands-on techniques and abstract algebraic...
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
Illustrative Mathematics
Half of a Recipe
Kids love to cook! What is a better place to learn mixed numbers than with a recipe? It is up to learners to decide how they want to divide this recipe in half. They may choose to model the mixed number and then divide the model by two....
Illustrative Mathematics
Running to School
The object of this activity is to compute how far Rosa ran to school. Given in the exercise is the fractional number of miles between home and school and the fractional distance Rosa ran. The commentary shows several ways to have your...