Abstract: The present invention is directed to a method and apparatus for teaching fractions to school age children. The invention provides an instrument having a base with at least two aligned scales of corresponding numerical indicia subdivided into different fractional units, as for example halves, thirds, quarters, sixths, and eighths. The base defines a space or gap between the different fractional scales so that a writing media, such as a piece of paper, may be inserted between the scales and moved either horizontally or vertically relative to one or more of the scales. The instrument provides an easy manner for a student to compare fractional units of the same integer and also to add and subtract both fractions and mixed numbers. In the preferred embodiment of the invention, the base of the instrument may be transparent so that all fractional scales are visible to the student simultaneously.