Simple machines are basic tools we use to make our work easier. Preschoolers can easily learn about simple machines through making inclined planes, levers, wheels and axles. The block center in a preschool setting is an excellent place to begin developing the preschooler's understanding of physical science related to simple machines.

Preschoolers enjoy building the inclined plane by placing a board or long flat block with one end on the floor and the other end resting higher, with one or more blocks stacked underneath. Preschoolers use the inclined plane to race toy cars, marbles and anything that rolls. Use tubes from paper towels or gift wrap to further stimulate the preschoolers' experiment.

Develop the preschooler's understanding of simple machines by using scientific vocabulary in your discussion. Comment on her simple machine by affirming her work, "I see you made an inclined plane. This is a great ramp for running cars." Encourage the preschooler to observe what happens when the inclined plane is higher with more blocks stacked beneath. Ask questions like, "What do you think will happen if you make your inclined plane slant lower?"

Preschoolers like the challenge of making things when they have the opportunity to use a hammer and other real tools. Collect an assortment of nails, jar lids and scraps of wood for your preschooler to make vehicles that roll. Children can invent their own vehicles with a little assistance, pounding the nails (axles) through the jar lid (wheel) and on to the wood block (body) of their vehicle. It is great fun to paint the vehicles bright colors. Talk with the children about ways wheels and axles make work simpler. Find examples of wheels and axles in the home and community.

Preschoolers love to play on the seesaw at the park. Help them make their own lever simple machine to lift heavy weight. Collect a basket of books or objects totaling about 10 pounds. You will also need a long plank and a concrete block.

Explain to the preschoolers that the basket of books is the load need to lift, the plank is the lever, and the concrete block is the fulcrum.. Demonstrate how to set up the lever. Have a child place the weight on one end of the lever and then step on the other end of the lever to lift the weight. When the child stands on the lever, he is the effort.

Experiment with moving the fulcrum to different places under the plank. Change the load weight. Can your preschooler lift an adult using the lever he made? Use simple machine vocabulary like load, fulcrum and lever as you experiment with lifting different objects different ways.