This set consists of a board with 225 round holes and 560 glass marbles in 7 colours, placed in a wooden index box with seven compartments, thus dividing them in groups of 80 marbles in the various hierarchies (from single units to millions). All wooden parts have a UNI EN 71-3 finishing.
SQUARE ROOT BOARD WITH MARBLES
This material can be used when the child has already worked with many psycho arithmetic materials and has a good knowledge of the decimal system and operations with big numbers and is acquainted with the hierarchies. This board has been developed to extract the square root of big numbers in a pleasant and fascinating way. It also allows to make many arithmetic operations.