This lesson is to be used as guided notes for a whole class.
The lesson begins by reviewing what a "factor" of a number is and uses this to introduce prime and composite numbers. Then students learn divisibility rules/tricks for 2, 3, and 5. After learning how to decide whether a number is prime or composite, they attempt some examples. Finally, they learn the Fundamental Theorem of Arithmetic and how to write prime factorizations by making factor trees.
The last 2 pages are a copy of the key.