Thousands of years ago, in ancient Egypt, there were men known as "rope-stretchers." It was their job to mark out the boundaries of fields and the foundations for houses, temples, and palaces. The...
Zero
Zero stands for nothing. If you have zero ice cream cones, then you have none at all. It may seem very silly to have a numeral for something that isn't there, but the numeral 0 is really very...
Ups and downs
Suppose someone asked you to lift a hippopotamus out of its hippopotamus-sized bathtub! It sounds impossible---but with a simple machine called a pulley, you could do it! A pulley is a special kind...
On your own
> Here are more things you can make with yarn, string, and rope.
Living in Two Worlds
Imagine how surprised these Indians were when they first saw men from Europe. In the Indians' world, clothes were made of animal skins. Their tools and weapons were made of wood and stone. But the...
Wind over the water
If you've ever read a poem or story about the sea, you're sure to have read about waves. If you've ever been to a seashore, you've seen waves come rolling in to slap the sand with a splash. If you've...
Christmas tree favorites
Which is your favorite kind of Christmas tree? People in the United States and Canada usually choose the balsam fir, the black spruce, or the Douglas fir. People in Britain, Germany, and most of...