The addition and subtraction operations are made on two wooden boards with the numbers 1 to 18 engraved on the upper side and in correspondence a grid of 10 rows of 18 small squares. The numbers are engraved with different intensity and the grids are divided vertically in two portions. The material includes two sets of PMMA strips: one box contains nine blue and nine red strips with the numbers 1 to 9 engraved on the far end and the other longer box contains 18 longer white strips, from 2 to 36 cm to be used with the subtractions. The multiplication board has 100 small round holes and the numbers 1 to 10 engraved on the upper side. On the left side you find an opening to slide in the small number tablets and in the left corner there is a place to put in the red counter. A wooden box with two compartments contains the red PMMA counter, the 1 to 10 engraved wooden tablets and 100 red micro lathed beads (plus 10 spare ones). The division board has 81 small round holes and the numbers 1 to 9 engraved on the upper side and holes to place the skittles in. A wooden box with two compartments contains 81 green micro lathed beads (plus 5 spare ones) and 9 micro lathed skittles with green varnish finishing. All wooden parts have a UNI EN 71-3 finishing.
KIT FOR BASIC ARITHMETIC OPERATIONS
Using this material of high esthetic quality to attract the child’s attention, from the age of around five it will be able to explore and master basic arithmetic operations by manipulating concrete objects. Moreover, by repeating the exercises, the child will progressively memorize the results of the arithmetic operations and this will be very useful for the future development of mathematical competences.