Originally defined as the ratio between the circumference of a circle and its diameter, pi — written as the Greek letter π — appears throughout mathematics, including in areas that are completely ...

If a number is a ratio of two integers (e.g., 1 over 10, -5 over 23, 1,543 over 10, etc.) then it is a rational number. Irrational numbers, when written as a decimal, they continue indefinitely ...

The ancient Greeks wanted to believe that the universe could be described in its entirety using only whole numbers and the ratios between them — fractions, or what we now call rational numbers. But ...