pie our squairs

Posted on June 26, 2014


pie our squairs… we often show why the area of a rectangle is the length times the width or the base times the height, but students so often get even more confounded with area vs. circumference of a circle. 

I’m thinking of including in My Idea Of A Pretty Good Math TUtorial a sidebar with Explanations of FOrmulae.   So for area of circle, I’d show you that the “r x r” represents the “base times height” idea… except that it’s too small… and multiplying by four would give you the area of a square outside the circle but we’d need to trim some off… and pi is the “trimmed” number, and that’s why pi r ^2 gives the area of a circle.   I got happy responses from a pre-algebra student today with it… though I dare say the other critical factor in the process was my concerted effort to use a non-anxiety-inducing tone of voice. I haven’t succeeded in capturing the late-night-radio voice that is on one of my video lessons… but it’s better. 

… and I’m almost caught up to where I was before vacation on The App.   This morning’s task:  fix two little details on the display….

… and hopefully, hopefully actually make headway on “level2.”  To my surprise I had already designed the “level” variable, tho’ I need to mess with how to design it with reusability and efficicent revisions in mind. 

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