An apparatus and system are disclosed for teaching mathematical concepts and "fact families." The apparatus comprises an educational toy block configured, in one embodiment, to help young children memorize basic numbers and number facts in an atmosphere focused solely on play. The toy block, in one embodiment, comprises a polygonal-shaped building block having a plurality of faces, wherein a first face features a first mathematical equation and a second face features a second mathematical equation. The toy block may include a display of multiple mathematical equations in order to facilitate teaching children how mathematical operations are related. In a further embodiment, the toy block displays one or more numbers that are numerical elements in a plurality of mathematical equations forming a "fact family."