Illustrative Mathematics
Eight Circles
We are used to finding the area of a circle by plugging the radius into an equation. Here, learners are required to go further to find multiple areas and calculate the difference. They must detect a pattern in order to figure out the...
Illustrative Mathematics
Designs
A resource that makes for excellent group work as middle schoolers explore the area and perimeter of different complex designs made up of squares and circles. The commentary gives a clear definition of perimeter, but suggests that group...
Illustrative Mathematics
How Many Leaves on a Tree? (Version 2)
A second attack at figuring out the number of leaves on a tree, this activity makes both an excellent follow-up to version 1 and a stand-alone activity. Learners practice setting parameters and deciding acceptable estimate precision, and...