
How to Become a LIGHTNING CALCULATOR.
Instantaneous Addition.
How to Add Two Columns at Once.
Multiplication.
Accurate Interest.
Equation of Payments.
The Lightning Calculator’s Addition.
Bank Discount.
How to Make Change.
Proof of Multiplication in Ten Seconds.
A lively handbook for anyone who wants to turn everyday numbers into swift, confident calculations. It begins with clear, step‑by‑step methods for rapid addition, teaching readers to line up digits, carry mentally, and even treat repeated numbers as multiplications. Simple examples walk you through the technique, showing how a few mental habits can make even long columns feel effortless.
The guide then expands to multiplication tricks that replace tedious pencil work with clever shortcuts—multiplying by 11, 101, or 5 using just a few mental moves. Readers learn how to handle fractions of numbers, such as “multiply by 2 ½” or “divide by 25,” with easy‑to‑remember rules. Throughout, the tone is practical and encouraging, inviting practice and promising noticeable speed gains.
Packed with concise tables and illustrative problems, the book offers a hands‑on approach that anyone—from shopkeepers to students—can apply right away. By the end of the first section, listeners will already feel more comfortable juggling numbers in their head, setting the stage for deeper mental‑math mastery.
Language
en
Duration
~16 minutes (16K characters)
Series
Multum in Parvo Library, Vol. I, No. 2, February, 1894.
Publisher of text edition
Project Gutenberg
Credits
Demian Katz, Craig Kirkwood, and the Online Distributed Proofreading Team at https://www.pgdp.net (Images courtesy of the Digital Library@Villanova University (http://digital.library.villanova.edu/))
Release date
Apr 13, 2021
Rights
Public domain in the USA.
Subjects
Some books outlast the names of the people who wrote them. When a work is credited to Anonymous, the mystery becomes part of its appeal, inviting readers to focus entirely on the story, ideas, or tradition behind it.
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