The study of numbers and their meanings is called numerology. This plays a role in magick, as you will see while you study it. The most widely used number in Wicca and witchcraft is the number 3 - this number has ancient power and is used in many religions other than Wicca. Odd numbers are generally preferred to even numbers, and 9 is used for particularly powerful or important magick (being 3 x 3, the idea is that it carries even more power than that of the number 3 itself).

   Numbers, like many things in magick, are intangible. They are concepts, and difficult to describe. Other animals have the ability distinguish between varying numbers of objects, or at least between "one" and "more than one." Whether they were "discovered" or "invented" depends on your point of view. I tend to think of them as inventions rather than inherent universal truths, but they can be used to describe universal truths and  (such as laws of physics, etc.). Mathematics is considered the queen of the sciences, and without it other sciences would be impossible. This in itself gives numbers great power. They allowed humans to participate in many common activities that we now take for granted - trade, measurement (such as in cooking), architecture, and describing the world around us in a way that could be easily communicated.

   As concepts, numbers originate in our minds. We cannot point to something in nature and say, "There, that is a number." So, numbers are an aspect of the mind. This can make them very useful in magick as a way for the conscious to communicate with the unconscious.  Numbers are of the conscious mind, and their use can connect this part of our mind with our unconscious. An example is the common practice of walking thrice about the circle during casting (to cleanse, consecrate, and cast).

   Below are some websites that will give you detailed information about numbers and numerology, and how they apply to your life: