Mental arithmetic

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221	PDF Document Add to Reading List Source URL: abacus.etherwork.net Language: English - Date: 2013-01-14 14:36:26 Suanpan Mental calculation Arithmetic Japanese numerals Abacus Mathematics Soroban
222	PDF Document Add to Reading List Source URL: business.nmsu.edu Language: English - Date: 2005-08-06 17:33:49 Andrew S. C. Ehrenberg Significant figures Marketing research Round-off error Mental calculation Marketing British people Education in the United Kingdom Arithmetic Numerical analysis Rounding