- integers
- modern teacher
- adding integers...
- a math trick-3
- adding and subtracting integers
- find LCM and GCD
- square numbers
- triangular numbers
- triangular numbers-1
- pythagorean triples-plato
- pythagorean triples-proclus
- pythagorean triples-euclid
- pascal's triangle
- a multiplication table
- The Sum of the First n Natural Numbers - Dynamic Proof
- russian multiplication
- a math trick-31
