A hand needs that many bones because a hand does a lot of different things! It waves, it grasps, it pinches, it snaps, it scoops, it plays Rock-Paper-Scissors, it pushes, it pulls and it does a lot of other things too! Our hands need to be in different shapes to do each of those things. In order to be flexible enough, we need a lot of bones.
Bones don’t bend. Imagine that your finger had only one bone. It couldn’t do very much. You could poke things, but that’s about it. Luckily each finger has 3 bones, so we can bend them to do thinks like type, write, and play instruments.
Sources & links
Manual Alphabet provided by Lifeprint.com < http://www.lifeprint.com/asl101/fingerspelling/> “A Patient’s Guide to Osteoarthritis of the Wrist Joint.” Hand University. 2001. 26 Jul. 2009. < http://www.handuniversity.com/topics.asp?Topic_ID=33> "human skeletal system." Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 26 Jul. 2009 < http://www.britannica.com/EBchecked/topic/547358/human-skeletal-system>