One of the most basic machines is the wheel and axle. You can help introduce preschoolers to this simple machine with a hands-on activity that will get them thinking about how objects move. Each child needs two jar lids (preferably two identical lids or at least similar in size), a straw and molding clay. If the straws are very long, cut them in half to make them easier for preschoolers to use. Instruct the children to use the clay to make the straw stick to the center of each lid. Assist them as needed. The finished products should roll on their own when the children push them forward.
Trains are an ideal teaching tool for young children. To introduce kids to the idea of a train, watch a short video or read a book about trains as a class. You can show them a toy train on a track to further enhance the lesson. Talk about what makes a train move; it has wheels and axles and is propelled by fuel. Allow them time to play with the toy trains and to look at more train books on their own. Finish by asking them to draw their own trains and illustrate what they learned about how a train works.
A jack-in-the-box is a classic toy that you can use to explain to preschoolers how wheels and gears interact to make things move. You can begin by showing the kids an egg beater (with a handle and visible gear) to illustrate how gears work to make motion. Next, show them a jack-in-the-box, turning the handle until the clown pops up. Ask the kids to go back to their desks and give them each a coloring sheet of a jack-in-the-box. Give the kids crayons and ask them to draw what they think the inside of the toy looks like. Does it have gears and wheels? If possible, you can open up one side of the jack-in-the-box when they are finished coloring to show them what is actually inside.
The concept of machines in motion can be easily illustrated in a playground setting. You can take the children outside and give them a lesson in their very own playground. Show the preschoolers the seesaw, merry-go-round and swings and ask them how each piece of equipment works. A couple of the kids can even demonstrate how the equipment works. Explain to them how the equipment is propelled and what makes each part move. Afterwards, give the kids some time to play on the playground.