Problem Pictures
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PP2 CD-ROM cover

This picture is taken from Problem Pictures Themes, a CD-ROM of photographs with activities for mathematics teaching.

Hoberman sphere

When it arrives in its box, the Hoberman sphere measures 240 mm across. Opened up, it grows to 830 mm, large enough to crawl inside.

How many coloured circles are there? Going around one circle, how many times does it touch other circles? What shapes are on the surface of the sphere? How many of each shape?


The photographs and screen images on this website are copyright and may not be reproduced without permission. Copyright Richard Phillips 2001/2007. Page updated 13 July 2005.