Source: http://www.khanacademy.org/math/cc-fourth-grade-math/cc-4th-fact-mult-topic/cc-4th-prime-composite/v/recognizing-prime-numbers
Source: http://www.youtube.com/watch?v=cRz4hW9SPPc&feature=youtu.be
Source: http://studyjams.scholastic.com/studyjams/jams/math/fractions/fractions.htm
Source: http://www.khanacademy.org/math/cc-third-grade-math/cc-3rd-fractions-topic/cc-3rd-fractions-meaning/v/fraction-basics