### Math Made Fun Fast and Easy

Packed with useful calculation methods, neat math tricks and amusing anecdotes, and all explained in a fun and very readable style.
Kenneth Williams

Knowing how to calculate quickly, without the need of a calculator or pen and paper is a very useful skill. Whether you need to divide a dinner bill among friends, double a recipe, compute for a discount or commission, or figure out how many more pages of your textbook you have to read, knowing math shortcuts can make your life so much easier.

The 25 short cuts included in this book are some of the most useful in everyday life and among the easiest to master.

### Note by the author

This collection of 25 Math Short Cuts is published in commemoration of the 25th Foundation Day of MSC Institute of Technology.

I have selected what I think will be most useful for everyone, whether you are students, teachers, professionals or plain folks who need to calculate every day. Much of the hard work in compiling this work is not in researching for materials because I know these short cuts by heart but in selecting what short cuts to include.

From our grade school years, many of us have learned many ways of simplifying calculations. I am sure that for most of us, “multiplying by 10” is one of the first math short cut we have learned. And we continue to use it, which is the reason why I did not include it here. Unfortunately, most of us have forgotten most of the short cuts we have been taught in the past. As for my case, I am somewhat “lazy” at calculations so that I always looked for easier ways of computing.

From my grade four teacher, I learned “squaring numbers ending in 5”.I developed more short cuts by applying what I learned in algebra to simplify arithmetic computations.To this was added some more techniques which I later picked-up from various books, like Trachtenberg Speed Mathematics by Jacow Trachtenberg and Turn on the Human Calculator in You by Scott Flansburg. Then there were also some very simple but elegant solutions which I learned when I began to study “Vedic Math” from the works of Prof. Kenneth Williams of the Vedic Maths Academy, UK.

I observed that my students enjoyed the short cuts that I shared with them and many came to love Math and actually improved their grades in the subject. I am also sure that these short cuts helped countless of my students pass the Philippine Science High School, UP Rural High School and UP entrance examinations.

Realizing that most readers like me, don’t want to read lengthy explanations, I tried to present the techniques in the form of examples. But sometimes I cited Sutras or “word formulas” used in Vedic Math, which are very useful in remembering the short cuts.

I hope that with these shortcuts the readers will eventually be able to do most calculations mentally. However, I also realized that many will have to write down the answer first before reciting it. So I will explain the procedures to arrive at a written answer using a mental solution. With a little practice, many can dispense with the written answer.

I also included some of the most common unit conversions where our techniques can be applied. While the Philippines officially adopted the SI or metric system, many still use the English or imperial measures such as pounds for body weight, feet and inches for height and quarts and gallon for liquid capacity. Using these conversions daily will enable us to practice these shortcuts.

I really enjoy using these short cuts so I included some pleasant experiences I had in using them. I hope all of you will enjoy them as much as I do.

Happy computing!

Virgilio Y. Prudente
Dec. 4, 2014

### Testimonials

I like your book, Ike - it's packed with useful calculation methods, neat maths tricks and amusing anecdotes, and all explained in a fun and very readable style.

Good luck with it and all your other excellent endeavours.

Kenneth R. Williams

The “25 Math Short-Cuts” is a great collection of mathematical short-cuts that everyone should know. With this book, the author tries to make Math an easy subject to understand. And it’s not often you see a math book written for all ages.

A must-have book for everyone!

Rex Aurelius C. Robielos
Dean, School of Industrial Engineering and Engineering Management
Mapua Institute of Technology