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Patent:GB191317890


Brevetto:GB 191317890
Titolo:Abacuses
Data:05.08.1913
Luogo:
Nazione:Gran Bretagna
Persona:Montessori, Maria (P)
Ditta:
Link interni:Abakus Lehrmittel
Keywords:
Link al brevetto:
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 GB191317890


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Aus der Patentschrift GB191317890

A device for teaching the writing of numerals employs differently coloured rows of ten beads, the left hand standard of the frame being marked to indicate the unit, tens, &c. rows. The numbers represented are written upon cards ruled with lines corre- sponding in colour, number, and sequence with the rows of beads.