The Sieve of Eratosthenes 
The Sieve of Eratosthenes is a method for finding all prime numbers
up to a given value.

Numbers and Geometry 
In the ancient Greek world, mathematics revolved around geometry.
Even multiplication could be done geometrically!

Modulo 5 Calculator 
This printable manipulative can be cut out and used by students to explore modulo
5.

Modulo Worksheet 
This is a one page worksheet with modulo 5 and modulo 12 problems.

Nicole Oresme's Proof: The Harmonic Series Diverges. 
The harmonic series, , is interesting in that, while
its terms get smaller and smaller, its sum does not converge.

St. Petersburg Paradox 
Would you bet 1 million dollars on a game with expected winnings of infinity? Read
this before you decide!

Napier's Rods 
This is a method of multiplying using rectangular sticks.
