Tuesday, August 17, 2010

The Mathematics of Circles

Awesome Drun Kit
Image Source: http://upload.wikimedia.org

Drums are one of the most marvelous use of circles that we've ever heard of here at Passy World. So let's get right into the beat of the Circle with a catchy Circles Song from Learning Upgrade website.

Here is another great circles tune, this time by Maths Teacher extraordinaire: Mr Dave Johnson:

So let's start taking a deeper look into the mathematics of circles.

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Here is a video all about the Circumference of any Circle:

Here is a video about how we can work backwards from the Circumference, to find out the radius of the circle:

And now for a video about how we can calculate the Area of a Circle:

Finally, here is a video about how we find the volume of a 3 dimensional circle, which is known as a "Sphere".

Now a really important part of working on Circles and spheres is the value of Pi.

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Pi is a mathematical constant whose value is the ratio of any circle's circumference to its diameter.

Eg. Pi = c divided by d.

Various people reciting Pi as fast as they can on You Tube take their own world records very seriously. The one to beat is how long to recite the first 100 digits
of the never ending decimals PI value.

A guy called Matt Parker originally set a World Record for reciting the first 100 digits. Then Michael J Lavery beat Matt's record, and pegged the time back to 25 seconds:

But Matt in true competitive spirit regained his world record back again with this improved effort.

This is in fact the fastest Pi recital time, that Passy World has managed to locate on YouTube thus far.

Finally, a very interesting video about a contender for the supreme Pi record of reciting it from memory to thousands and thousands of decimal places !

All this talk about Pi has made me quite peckish, and so I'm off for a cup of tea and a nice little custard pie I got from the shops this morning.

Big Passy Wasabi

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