An educational toy which includes a base board having lines of female mounting portions longitudinally disposed at the first, third, fifth, and six lines and a line of signs of multiplication longitudinally disposed at the second line and a line of sings of equality at the fourth line, a set of setting...http://www.google.fr/patents/US5653594?utm_source=gb-gplus-shareBrevet US5653594 - Educational toy for learning multiplication
