Are you fascinated by so-called "lightning calculators"? Want to learn what they know? This 2011 calendar is jam-packed with practical techniques for fast mental calculation. Each month is dedicated to a different type of calculation, from simple multiplication and day-date calculations to square roots and multi-digit logarithms. Each day presents practice problems based on the date itself---nearly 4000 exercises overall built right into the calendar (with answers!). This is a uniquely wonderful and interactive calendar for the mathematically inspired.
The calendar is presented as a coil-bound book; simply turn it sideways to use it.
(Note that the cover and back pages appear blurry in the preview below because they are higher resolution than the previewer can handle well.)
