142857 - Number theory, classroom projects, exploration, and activities surrounding an unusual number with mysterious properties.

Use Happy Numbers in your math classroom at either elementary or secondary level. A variety of educational uses.

Studying methods that can be used to determine whether a number is evenly divisible by other numbers is an important topic in elementary number theory

Greatest Common Factor - easy method for finding it

Helping a child remember the difference between a prime number and a composite number - Which is which?

Number theory topic: Modular Arithmetic, the arithmetic of remainders, and congruneces

The factors of a natural number which are prime numbers are called the Prime Factors of that natural number.

Comparison of Decimal (base 10) number system and Binary (base 2) number system, how to convert from one to the other