Number Theory

Divisibility Rules: http://www.youtube.com/watch?v=QyCVcukDsaQ&feature=plcp

Factors: https://www.youtube.com/watch?v=3q6oqbYF7iY

GCF: http://www.youtube.com/watch?v=_5bloYXScUE&feature=plcp

LCM: https://www.youtube.com/watch?v=b6qehkDuioQ

Primes and Composites: http://www.khanacademy.org/math/arithmetic/factors-multiples/v/recognizing-prime-numbers

Prime, Composite, Multiples, and Prime Factorization (will not work on iPad -- computer/laptop only): http://www.learnalberta.ca/content/mesg/html/math6web/index.html?page=lessons&lesson=m6lessonshell07.swf

Primes Factorization: http://www.youtube.com/watch?v=qGkK8xkWs6U