Numbers set celebrates its roots.

Move over, Ben Franklin. Your 300th anniversary celebration has passed. It's Leonhard Euler's turn. Who? You know, Leonhard Euler (pronounced

Oiler

), one of the world's most prolific mathematicians and "intellectual ancestor" of Sudoku, a logic puzzle of squares that has become highly popular in recent years.

Mathematics professors and teachers worldwide are giddy over the forthcoming tercentenary of the birth of this numbers hero whose work is important in engineering, physics and astronomy; in Euler's homeland, Switzerland, they're coming out with a comic book about his life, called Euler: A Man To Be Reckoned With.

"Euler is to math as Mozart is to music," says Muhlenberg College math professor William Dunham, who has written a book on Euler.

The Mathematical Association of America is planning celebrations throughout the year, including an overseas tour for educators in July to cities where he lived.

The association also is publishing Euler books, scheduling talks at professional meetings, and printing posters hailing

See EULER on A7

To test Leonhard Euler's polyhedral formula:

1. Pick up any cube or box.

2. Count the number of vertices (corners), edges and faces.

3. Add the number of vertices and faces.

4. Subtract the number of edges from that number, and you'll end up with two. Always.

Note: You should count eight vertices, 12 edges and six faces.

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EULER

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For more on Leonhard Euler, go to http://go.philly.com/mathEndText