








As the title suggests, this book is a comprehensive guide to mental arithmetic. It covers addition, subtraction, multiplication, and division, as well as fractions, decimals, and percentages. Written by George Albert Wentworth, a renowned mathematics professor, this book is...

As the title suggests, this book is a comprehensive guide to mental arithmetic. It covers addition, subtraction, multiplication, and division, as well as fractions, decimals, and percentages. Written by George Albert Wentworth, a renowned mathematics professor, this book is...