Every four years something funny happens with our calendars -- we add a day! Why do we do this? Discover the science behind leap year.

What's the difference between renewable and non-renewable energy? Help your student discover the various forms of energy we use each day.

Read about Alexander Graham Bell, the man who made it possible for us to stay connected all day long, in this biography that comes with a science experiment.

Test your knowledge of electrical energy with this third- and fourth-grade worksheet!