Simple Machines

Bonnie Anderson Libby School Annex
5338 S. Loomis
Chicago IL 60609
(312) 535-9350


This lesson was designed for students in grades 2-4.
The students will be able to identify the six simple machines and how they are
used in our lives. They will gain a basic understanding of the use of force and

Materials Needed:

For Inclined Plane - Weights (identical for each group), Spring scales, Ramps
(cardboard, approximately 5"x30")

For Wedge - Child's ax, "Blocks" of cardboard (use masking tape to tape together
8 4" squares of cardboard to form a block, simulating a wood block), 2" bolts
with hex heads, 2" nails with large heads, Pencils, Hand-held pencil sharpeners,
Iced oatmeal cookies, Oranges, Plastic knives

For Screw - Pencils, Paper triangle shapes (8" long), 2" screws, "Blocks" of

For Lever - 3 stuffed teddy bears (2 the same size and 1 much larger), Cement
block or wood block , Tongue depressors, Pencils, Sugar cubes or mini-
marshmallows, Child's toys (rakes, shovels, hoes, wheelbarrow, broom, Nerf Bat,
Nerf Football, canoe and oar)

For Wheel and Axle - Small child's bike (just the front wheel and handlebars
will do), Large teddy bear, Large photos of Ferris Wheel, Merry-Go-Round
(child's toys work very well), Screwdrivers, 2" screws, "Blocks" of cardboard

For Pulley - Small Kermit the Frog doll, Flagpole about 3' high with fixed
pulley and flag, Gallows-type contraption with fixed pulley at top, movable
pulley suspending weight at bottom, Spring scale, Snow White doll, Model of
well with fixed pulley


Inclined Plane - Draw 2 identical houses on board, except one house has a ramp
to get to the door, and the other has stairs. Discuss the houses, and have the
children tell you that the house with the ramp probably has a person in a
wheelchair living there. Discuss whether it is easier to lift that person
straight up to the door or to use the ramp. Use the cardboard ramps to
demonstrate the wheelchair ramp in the house. Measure the effort that you need
to lift a weight straight up to the height of 12", then measure the effort that
you need to pull the same weight up the ramp. Determine which method required
less effort. (Be sure to clarify the word plane as a multi-meaning word, since
we are not referring to an airplane.) Elicit from the children other examples
they may have seen of inclined planes.

Wedge - Display the child's ax and reference it to the tools the settlers and
Indians used in "Pocahontas" or the woodcutter's ax in "Little Red Riding Hood".
Help the children to describe the ax as being a triangle or a wedge shape.

Distribute a cardboard block, bolt, and nail to each group. Ask the children
to compare the bottom of the bolt and the nail, then to compare the effort
required to push each into the block.

Distribute a pencil to each child. Ask them to sharpen the pencils without any
help. Distribute the sharpeners, have the children observe the edge of the
sharpener is a very sharp wedge, then allow them to use the sharpeners to
sharpen the pencils. Elicit from the children other examples of wedges they may
have seen.

Distribute a plastic knife and either an iced oatmeal cookie or an orange to
each student. Ask them to pretend they are very young and have no teeth, so
they will have to keep their lips curled around their teeth. Then have them try
to eat their cookie or orange without using teeth or fingernails. Have them
look at their knife and determine that the knife is a wedge they can use to peel
the orange or cut the cookie. Finally, have the students feel their teeth and
determine that they are sharp and also function as a wedge they can use to cut
the cookie or peel the orange.

Screw - Ask the children to wind the paper triangle around their pencil (so
that it looks like a screw). Compare the screw to the nail and the bolt and
then ask the children to use their fingers to put the screw into the cardboard
block. The children should be able to recognize that a screw is actually an
inclined plane wound around. Elicit from the children places that they have
seen screws used, such as drills, etc.

Lever - Set up a see-saw with a board and a cement block. Have the two small
teddy bears "play" on the see-saw, then have the large bear come to "play".
When he jumps on one side of the see-saw, one of the small bears will fly off.
Ask the children why this happened and they should indicate that the large bear
was too big and/or he ran and jumped with too much force. Define the see-saw as
a lever, and point out that a lever has to have 3 components - a fulcrum, a
load, and a force.

Distribute a tongue depressor, pencil, and several sugar cubes or mini-
marshmallows to each child. Have the children make their own see-saws. They
may experiment with moving the fulcrum (pencil) and the amount of force which
they apply to the load.

Ask for volunteers to come forward to demonstrate how "Old McDonald" used tools
like shovels, hoes, rakes, wheelbarrows. (Sing "Old McDonald".) Ask for a
volunteer to demonstrate the use of a broom. Ask for a volunteer to demonstrate
use of the bat and ball. (Sing "Take Me Out to the Ball Game.) Ask for a
volunteer to demonstrate use of the football. (Sing "Bear Down Chicago Bears".)
Display the toy canoe and oar and demonstrate their use. The children should be
able to indicate that all of the toys from this demonstration are examples of

Wheel and Axle - Display the front wheel and pedals from a child's tricycle.
Help the teddy bear ride the bike. Demonstrate how the pedals (axle) turn the
wheel so that the wheel can travel a great distance. Explain how a ferris wheel
and a merry-go-round function as wheels and axles.

Distribute the screwdrivers, screws, and cardboard blocks. Have the children
use their screwdriver to put the screw into the cardboard block. Explain that a
screwdriver is a wheel and axle, with the wheel turning the axle and increasing
the force applied. Try to elicit from the children the understanding that a
doorknob is another example of a wheel and axle.

Pulley - Display the flagpole and tell the children that Kermit has a job to do
- raise the flag! His problem is that he cannot jump to the top of the flagpole
to pull the flag up. He finally tries pulling on the rope, which will raise the
flag. Have the children observe that Kermit pulled down, but the flag went up,
so a "fixed" pulley changes the direction of force. (Be sure to clarify for the
children that "fixed" is a multi-meaning word, meaning stationary, not the
opposite of broken.)

Use the gallows contraption to illustrate the use of a movable pulley.
Determine the force necessary to raise a wooden block, then compare that to the
force necessary to raise the block using the movable pulley. The children will
be able to see that a movable pulley reduces effort.

Stand Snow White at the well. Tell the children that Snow White has to work
very hard for the wicked Queen. One of her jobs is to bring water from the well
every day. Demonstrate that Snow White uses a pulley to help her bring up

Performance Assessment:

In each example of a simple machine, the children should be able to explain how
the machine helped to reduce effort, increase force, or change the direction of
force. They should be able to give several examples of simple machines they see
and use every day.
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