A math teaching tool is provided which can perform teaching more efficiently. The math teaching tool is characterized in the followings. It includes a vessel and a plurality of marbles disposed inside the vessel; the vessel includes a partition defining a boundary of a plurality of regions and a communication part allowing the plurality of regions defined by the partition to communicate with each other; at least one region of the plurality of regions of the vessel is configured so that the plurality of marbles are arrayed into a plurality of lines per unit of five marbles along a first direction of the vessel; and the plurality of marbles include five marbles connected together.