Here are some articles that talk about the many kinds of numbers you'll find on your digital SLR lenses.
Assignment: Learn the Principles of Animation and Analyze how they are used in animations you watch:
Learn to identify at least 2 principles of animation. Watch these animations and write down what you see when you find them.
Where does the artist use the principles of animation in this claymation? https://www.youtube.com/watch?v=fCWSQcaWoNk
Timmothy Hittle has another claymation. The Potato Hunter Where does he use the principles of animation in it?
How does Jeff Chiba Stearns from Meditating Bunny Studios use animation principles in the Yellow Sticky Note drawings he animates?
All about animation: http://karmatoons.com/index.htm