| 摘要 |
PROBLEM TO BE SOLVED: To easily learn calculations of addition and subtraction including negative numbers. SOLUTION: This calculation learning tool comprises a positive number display part 11 in which positive numbers are displayed upwardly from 1 in ascending order at equal intervals of 1, a negative number display part 23 in which negative numbers are displayed downwardly from -1 in descending order at equal intervals of 1 and are also arranged in the lower part of the positive number display part 11 across starting point corresponding to 0, an indication part 32 which is arranged to be vertically movable along the positive number display part 11 and the negative number display part 23 and indicates an arbitrary number, plural balls 3 as thick as the display intervals of the positive and negative numbers, a sliding plate 15 which allows the balls 3 to be mounted thereon when it is made to slide on the side of the indication part 32 and let the ball fall down when it is made to slide on the side leaving from the indication part 32, and a ball receiver 33 which is arranged to allow the balls to be mounted on the upper face, and also vertically moves along with the indication part 32, with the upper face arranged almost right at the side of the number indicated by the indication part 32, and further catches the fallen balls 3.
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