Good Math

3Real Numbers

Now we know about the naturals and the integers. That’s a good start. But there are more kinds of numbers than that: there are fractions and irrationals and…well, we’ll come to that later. But the next step in understanding numbers is looking at numbers that have non-integer parts, numbers that fit into the gaps between integers, like 1/2, –2/3, and π.

For now, we’ll look at the next kind of numbers—numbers with a non-integer part, otherwise known as the real numbers.

Before I go into detail, I need to say up front that I hate the term “real numbers.” It implies that other kinds of numbers are not real, which is silly, annoying, frustrating, and not true. In fact, the term was originally coined as a counterpart to imaginary ...