Trevor Lipscombe graduated with an undergraduate degree in theoretical physics from Queen Mary College, University of London, and then obtained a doctorate in theoretical physics from the University of Oxford. He is the author, with Alice Calaprice, of “Albert Einstein: A Biography,” and sole author of “The Physics of Rugby,” which was selected as one of the best ten physics books of 2009. He edited the critical edition of Saint John Henry Newman's novel “Loss and Gain.” Trevor was a postdoctoral researcher at the Levich Institute at the City College of New York, but has also worked in a homeless shelter, a physics journal, and three university presses. He remains fond of finding ways to present science-related materials simply.

If you think mental arithmetic is out of date in the 21st century, think again. This engaging book is about insight and interestingness beyond the simple utility of quicker calculations. The general style is original and characterful, and makes the book distinctive.

• Preface Introduction Challenge 1: Arithmetical Advice 2: Speedier Sums and Subtractions Interlude I: The Magic of 111,111 3: Accounting for Taste -- Adding Columns Quickly Interlude II: Checking, Check Digits, and Casting out Nines 4: Quicker Quotients and Pleasing Products -- Multiply and Divide by Specific Numbers Interlude III: Doomsday 5: Calculations with Constraints -- Multiply and Divide by Numbers with Specific Properties Interlude IV: Multicultural Multiplication 6: Super Powers -- Calculate Squares, Square Roots, Cube Roots, and More 7: Close-Enough Calculations -- Quick and Accurate Approximations Interlude V: Approximating the Number of Space Aliens 8: Multiplying Irrationally The Grand Finale Further Reading Appendix I: Calculating Doomsday Appendix II: The Squares from 1 to 100

Trevor Lipscombe graduated with an undergraduate degree in theoretical physics from Queen Mary College, University of London, and then obtained a doctorate in theoretical physics from the University of Oxford. He is the author, with Alice Calaprice, of “Albert Einstein: A Biography,” and sole author of “The Physics of Rugby,” which was selected as one of the best ten physics books of 2009. He edited the critical edition of Saint John Henry Newman's novel “Loss and Gain.” Trevor was a postdoctoral researcher at the Levich Institute at the City College of New York, but has also worked in a homeless shelter, a physics journal, and three university presses. He remains fond of finding ways to present science-related materials simply.

If you think mental arithmetic is out of date in the 21st century, think again. This engaging book is about insight and interestingness beyond the simple utility of quicker calculations. The general style is original and characterful, and makes the book distinctive.

• Preface Introduction Challenge 1: Arithmetical Advice 2: Speedier Sums and Subtractions Interlude I: The Magic of 111,111 3: Accounting for Taste -- Adding Columns Quickly Interlude II: Checking, Check Digits, and Casting out Nines 4: Quicker Quotients and Pleasing Products -- Multiply and Divide by Specific Numbers Interlude III: Doomsday 5: Calculations with Constraints -- Multiply and Divide by Numbers with Specific Properties Interlude IV: Multicultural Multiplication 6: Super Powers -- Calculate Squares, Square Roots, Cube Roots, and More 7: Close-Enough Calculations -- Quick and Accurate Approximations Interlude V: Approximating the Number of Space Aliens 8: Multiplying Irrationally The Grand Finale Further Reading Appendix I: Calculating Doomsday Appendix II: The Squares from 1 to 100