| 摘要 |
PROBLEM TO BE SOLVED: To provide an addition and subtraction learning tool which can be handled without losing a plurality of beads used for learning and spare beads, can cope with the change of the number to be learned, can be compactly stored, and can be attracted and fixed to a blackboard by using magnets. SOLUTION: In a state where neither the beads used for learning nor the spare beads can be added to or removed from the frame 21 of an arch frame assembly 2, frame end parts 15 and 16 are fixed to a movable stopper 37, the beads used for learning are arranged on the upper part of the body 3, and the spare beads are arranged in the inner case 35 of the body. The arch frame assembly 2 has a structure for keeping the erected condition with respect to the body 3, and is so constituted that the beads can be replaced in a horizontal state. COPYRIGHT: (C)2009,JPO&INPIT
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