Raidho

 
Afiliado: 14/07/2016
I never saw a wild thing sorry for itself...
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Mental calculation

Nikolay Petrovich Bogdanov-Belsky. Mental calculation. In the public school of S.A. Rachinsky (1895).

231011962

No calculators. No paper. No pens. Only own wits.
A rural Russian school. The late XIXth century.
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