Circumference of a circle!

Well today we measured circles and we measured diameters and we divided circumference by diameters to find that about 3.2ish diameters will fit around a circle.


Then we shared that that means we can calculate the circumference of a circle if all we know about it is its diameter! And the way to do that is with the relationship:

C= 3.14 x diameter or

C= 3.14 x d or

C=  π x d

I would definitely encourage students to always write down the equation. And they can use calculators to do the calculations.


Now, even though we did all that pre-work at estimating pi, a lot of kids seemed to not make the connection between circumference and diameter and pi. I consulted with the other 6th grade math teachers and they said that I shouldn't worry and that the kids really just need more practice in recognizing and using the relationship. 


But in the mean time, if your child seems really lost about where that equation came from, they might find this video from the Khan Academy handy: