Abstract: A device and method for teaching, solving, and/or illustrating mathematical principles and equations is disclosed. The device comprises a set of increasing numerical values arrayed on a spectrum, each numerical value represented by a length, each length comprising a visual marker representative of the numerical value; wherein the visual marker is repeatedly displayed on the spectrum in a pattern corresponding to or at intervals in accordance with the visual marker's numerical value. Alternatively, the device may comprise a set of increasing numerical values on a spectrum, each numerical value represented by a length, each length comprising distinct visual markers representative of mathematical factors of the numerical value.