Object: Some nails and a magnet.

Good morning, boys and girls. I brought with me this morning something that is a lot of fun to play with when you have nothing else to do. (Show them the magnet.) Of course, it is not always used as a toy. Sometimes it is a very valuable tool. How many of you know what this is? (Let them answer.) That's right, it is a magnet. Have you ever used one? (Let them answer.) Well, let's think about what a magnet does while I show you something else.

(Take out the nails and spread them over the floor.) Have you ever looked at a bunch of nails when they are spread out like this? Can you tell which direction they are heading? (Let them answer.) It's kind of a mess, isn't it? The nails should have a leader, something to bring …