standard_description: Derive using similarity the fact that the length of the arc intercepted by an angle is proportional to the radius, and define the radian measure of the angle as the constant of proportionality; derive the formula for the area of a sector.
problem_activity: Stage 1: Add
Required Preparation
Materials to Gather
Connecting cubes
Counters
Materials to Copy
Blackline Masters
5-Frame
Number Mat 1–5
5-frames Stages 1 and 2 Recording Sheet

Narrative
Students begin with a full 5-frame and roll to see how many counters to add.


aligns: no