1001 задача для умственного счета

The collection presents hundreds of short mental-arithmetic problems with immediate answers, arranged for classroom use and individual practice. Exercises place calculations in everyday situations—trade and prices, land and cloth measures, weights, time and calendars, wages and expenses—often requiring unit conversions, proportions, and quick multi-step arithmetic. Problems vary in complexity and emphasize practical techniques for fast, accurate computation using historical units and currency, reinforcing number sense, estimation, and routine problem-solving rather than formal theory.