When you estimate a number you decide approximately, or roughly, how big that number is. To estimate accurately, you need to have a good understanding of the value and order of numbers. A number line ...

Tape measures. Rulers. Graphs. The gas gauge in your car, and the icon on your favorite digital device showing battery power. The number line and its cousins -- notations that map numbers onto space ...

The Kakeya conjecture predicts how much room you need to point a line in every direction. In one number system after another — with one important exception — mathematicians have been proving it true.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Hi, my name is Miss James and I can't wait to find out just how clever you are in our lesson today. For ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Hi there. I'm Miss James and I'm so excited to be learning with you today. For this lesson, all you ...