The "real" numbers, the "imaginary" numbers, the "complex numbers, etc. are all ordered sets. Unfortunately, some of these labels have other meanings outside of math. Outside of math, "real" usually means something tangible that is perceived by at least one of our senses, and "imaginary" means something intangible and not perceived by our senses.

No. Numbers are not real but can have a real effect on our lives if we assign them real values. The perfect example is the acceptance of something invented called money, and to go along with it, the assigned money value for everything.

Prime numbers are found hidden in nature, but humans have made spectacular use of them, writes mathematician Marcus du Sautoy.

From pine cones to spiral galaxies, fascinating patterns of the Fibonacci sequence occur naturally in nature. Find out how this ancient sequence manifests in our world and beyond. (Credit: Kate Babiy/Shutterstock) Nature is disordered, messy, chaotic.

The Fibonacci sequence works in nature, too, as a corresponding ratio that reflects various patterns in nature — think the nearly perfect spiral of a nautilus shell and the intimidating swirl of a hurricane.