This describes Number theory, statistics, patterns, series of equations, and other methods of solving math problems. At the lower levels, algebra and perhaps even a little probability is known. At the highest levels, you have mastered the art of making numbers fit. This skill will be needed for complex rolls to finish math problems that arise in science, engineering, and technology. It is a crucial skill for anyone planning on difficult work.
Just assume everyone is capable of basic arithmetic, unless they don't seem the type.