Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in require_once() (line 341 of /home/n9esbwprkar5/public_html/domains/circles/includes/module.inc).
Can you arrange a set of numbers in pairs, so that the sum of each pair is a perfect square? What if the sums must be primes? What if the sums must all be distinct? Discover the surprising variations in this simple challenge.
In how many ways can you draw a star using all the vertices of a polygon, without lifting your pencil from the paper? Are there some polygons for which it's not possible?
Explore the surprising variations in conceptually simple sequences of numbers, constructed by applying one of two operations to generate each successive term. Can you make the sequence return to its starting value?
Fold a long strip of paper in half several times. Can you see a pattern in the creases formed along the length of the paper? What sorts of route do we trace if we use the creases to direct our turns along a path?