For thousands of years, people judged the temperature by how they felt. To check the heat of an oven, cooks put a hand into the oven. If the weather felt cold, people put on more clothes. Long, long...
Back and forth and up and down numbers
The number one is more than zero, of course. But can a one ever be less than zero? Yes, it can! Suppose you are standing at the middle of a long line drawn on the ground. Let's call the place...
How far is it?
A map may be millions of times smaller than the real land it pictures. So how can you find out how far it is from one place to another? To find out, you use a "measuring stick" called a scale. Scale...