Professional 11-Column Math Calculation Tool for Kids Abacus For Students : LARGE DIMENSION: arithmetic abacus, a classic tool that is still fully functional This is the perfect size for children's use and decoration : it is round, smooth and , 1 above and 4 beads below out of 11 CONVENIENT TO USE: Beads slide easily, there are pod pads on the back, and the abacus placed on the table has some non-slip, reducing wear on the back of the abacus EDUCATIONAL: Never miss this education Your children show interest in math Enables children to count and more complex calculations : Can be used calculator in office, educational tool for teacher or great for abacus collectors, boys and girls Specification: Material: ABS plastic; Size: 17,5 cm x 6 cm x 1,5 cm/6,89 2,36 0,59 inch) contains: 1 set of 11-digit abacus rods