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

Do you measure distance in inches or seconds? When do you use miles? Answer these and more with this third-grade worksheet about the customary system of measurement! 

This science worksheet tells all about James Watt, the man that powered the Industrial Revolution.

Searching for a worksheet that will give your kid help with his science skills? This printable will challenge his knowledge of the metric system.

Get to know the Apollo 11 space mission in this science and history worksheet!

Mix, boil, and toast your way to understanding energy transformations with this fourth-grade worksheet!