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.

Although few of us think of numbers in spatial terms 5, psychophysical evidence suggests that the mental representation of numbers has a spatial nature, possibly with a left–right orientation 6. First ...

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 ...

Real numbers are, in fact, pretty much any number that you can think of. This can include whole numbers or integers, fractions, rational numbers and irrational numbers. Real numbers can be positive or ...