Secrets of Mental Math24.pdf

SECRE+S
OF
MEN+AL MA+H
The Mathemagician’s Guide to Lightning Calculation
and Amazing Math Tricks
Arthur Benjamin
and Michael Shermer


Acknowledgments
The authors wish to thank Steve Ross and Katie McHugh at
Random House for their support of this book. Special thanks to
Natalya St. Clair for typesetting the initial draft, which was
partly supported by a grant from the Mellon Foundation.
Arthur Benjamin especially wants to acknowledge those who
inspired him to become both a mathematician and a magician—
cognitive psychologist William G. Chase, magicians Paul Gertner
and James Randi, and mathematicians Alan J. Goldman and
Edward R. Scheinerman. Finally, thanks to all of my colleagues
and students at Harvey Mudd College, and to my wife, Deena,
and daughters, Laurel and Ariel, for constant inspiration