Magic with Numbers


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, Harmonic Series: sum(1/n, n=1..infinity), 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.