The Mole

The mole is unit that is commonly used to express the amount of a substance. It is a combination of a regular mass in grams and the atomic mass. It can be expressed by the Avogadro constant which is about 6.02 x 1023 .

http://tedx.tumblr.com/post/64880189576/happy-mole-day-no-no-no-not-that-kind-of-mole

Check out the link under the photo. It has an awesome video explaining the mole. A mole also acts as a converting factor. It can be used to express the mass of a finite number of atoms or vice versa. 

http://chemistryiseasy.com/

Check out the link under the second photo also. It gives a good explanation on mole math and the different kinds of situations the mole can be used in.