## Illegal, Unlucky, and Forbidden Numbers

We use numbers a lot everyday that we sometimes do not even notice.  They have become very useful that we depend on them all our lives. But did you know that there are numbers that are believed by many to be unlucky? Did you know that there are numbers that are illegal to use in some places?

In this post, I’ll give you some interesting examples of such numbers. » Read more

## How Old Was Diophantus?

Diophantus was a Greek mathematician and the author of Arithmetica.  He is famous for his Diophantine equations which eventually inspired Fermat to propose the Fermat’s Last Theorem. Little is known about him, and much of knowledge of his life is derived from a 5th century Greek anthology of games and puzzles.  One of this puzzles is known as his epitaph.

‘Here lies Diophantus,’ the wonder behold.
Through art algebraic, the stone tells how old:
‘God gave him his boyhood one-sixth of his life,
One twelfth more as youth while whiskers grew rife;
And then yet one-seventh ere marriage begun;
In five years there came a bouncing new son.
Alas, the dear child of master and sage
After attaining half the measure of his father’s life chill fate took him.
After consoling his fate by the science of numbers for four years, he ended his life.’

This means that Diophantus lived 1/6th of his life as youth, and then grew a beard after 1/12th of his life.  He married after 1/7th more of his life, and had a son five years later. His son lived as long as him, and Diophantus died four years after his son’s death.

Can you determine the age of Diophantus when he died?

## Dancing and Mathematics? Really?

Sometimes, mathematics appears in places that we sometimes least expect it to be — like in dancing.

Although the figure above is bit of a stretch, Erik Stern (educator, choreographer) and Karl Shaffer (choreographer and mathematician) from     John F. Kennedy Center for the Performing Arts in Washington literally integrated mathematics and dancing in what they called Math Dance. In Math Dance, a class looks like a dance lesson, but it is also a new way  of teaching mathematics.  Math Dance involves translating patterns into choreography and translating patterns to mathematics.  Some of the mathematics learned in math dance are polyhedral geometry, symmetry, the mathematics of rhythm, and variations on dissection puzzles such as tangrams.