Understanding Pi as a ratio

Objective To use the relationship C = πD to find the circumference of a circle. 

Lesson Plan
Baked bean (or other tin)

Rulers and string

Print out of slide3 (and  other slides depending on how you plan your lesson)
https://www.youtube.com/watch?v=eOMZtBacarY The Code Episode 1 from 24.46 to 28.36.