McGraw-Hill Science Return to Book List
Grade 3
Science Magazine & World of Science
Lift It, Push It, Pull It, Topic 6: More Simple Machines
Simple Machines on a Playground
Keyword: RAMP

Did You Know...
Simple machines are part of your body! Your arms act like levers when you lift something. Your front teeth act like wedges when you bite into food.


Look, Learn, and Do: Projects

Learn how to make all sorts of fun things based on simple machines. Be sure to talk to your parent, guardian, or teacher before you start a project.


  1. Fill in the blank: A blimp can float in the air because of its natural _____.

  2. In the greenhouse experiment, what kind of seeds are best to plant? Why?

  3. Which of the supplies in the compass experiment serves as a lever?


Inventions, with Wild and Wacky Games, from National Geographic

Click the monkey, and you're on your way! Join Professor Lou Knee and the gang to learn about inventions. See if you can spot simple machines in action! (NOTE: Your computer needs Shockwave to see this site.)


  1. When was the vacuum cleaner invented?

  2. Who developed the first radio?

  3. When were the first false teeth made? What were they made of?