Mental Math

Tricks To Become A Human Calculator

Abhishek VR

• Publisher: Ofpad
• Year: 2019
• Print ISBN: 9789352911110
• eBook ISBN: 9789355784667
• Topic: Mathematics
• Subtopic: Arithmetic
• Index: Mathematics

Discover the Mental Math Secrets to Become a Human Calculator!

Schools taught you a way to do math that works when you have a pen & paper. But the same methods, takes a lot of effort when you have to do math in your head. This is because it uses a lot of your working memory (the short term memory used to complete a mental task).

For example, try to mentally multiply 73, 201 x 3. It might take only a few seconds to multiply the individual digits. But if you multiply right to left the way you learnt in school, you will rely on your working memory. You will use it to recall every single digit you calculate to put it back together and get your final answer. You may even find yourself calculating some digits again because you forgot one of the numbers.

The difficulty increases further when you have to multiply larger numbers like 732 x 323. You will have to remember numbers across many steps. Mental arithmetic would be a lot easier to do in your head if you didn't have to remember so many numbers.

In school, you learnt to write the down numbers as you calculate to free up your working memory. In mental math, there are many other ways to do the same thing.

One of the tricks to free up your working memory is to calculate from left to right instead of right to left. Try multiplying 73, 201 x 3 from left to right, starting from 7 x 3 and ending with 1 x 3. You will find yourself calling out the answer before you even finish the whole problem.

You can use this trick to solve any math problem in the future. But we have just scratched the surface. There are many more tricks inside the book that make doing mental math as easy as reading a comic.

Here is a glimpse of what you will be able to master:

•Mentally add large numbers (Example: Add 8739 + 5492 in your head in seconds)

•Subtract numbers fast. (Example: Mentally subtract 7520 - 4998 without writing anything down)

•Multiplication tricks to multiply three-digit numbers. (Example: Multiply 323 x 123 in your head)

•Square large numbers in seconds (Example: Calculate 64 x 64 faster than a calculator)

•Mentally divide large numbers (Example: Divide 601324 by 73 entirely in your head)

•Quickly check a calculation with 90% accuracy without re-calculating

•Overcome math anxiety

•Cement your mental math skills with bonus weekly training.

This book only has the best techniques used by over 27 mental and Vedic math experts across the world. The techniques in this book are so simple you will wonder why nobody taught you this before. You will be able to master it, even if you have failed math in school.

Imagine waking up tomorrow being able to do lightning fast math in your head. Your family & friends will look at you like you are some kind of a genius. Since you do the calculations in your head, you will acquire better mental habits in the process. So you will not just look like a genius. You will actually be one.

Buy Now To Become A Human Calculator

Every minute you wait to buy this book, is another minute you don't see the benefit of being good with math & numbers. Put the power of mental math to work in your life so you can quickly & easily:

• make math and numbers more useful

•develop better memory habits

•increase concentration

•develop new ways to think

•and do speed math entirely in your head faster than a calculator!

Get your copy today!

A MUST BUY for students of Vedic Mathematics, GMAT, GRE, SAT, Case Study Interview and Case Interview.

Chapter 1 - What Is Ofpad Mental Math System?

The Ofpad Mental Math system is the only system to do math in your head faster than a calculator making math your new superpower. These radically simple techniques for mental math will work for you even if you hate math and if you are terrible at math, to begin with.

This mental math book was written after analysing the techniques used by over 27 mental math geniuses across the world, from countries including Sweden, India and China. I uncovered these hidden patterns and unique (sometimes 'odd') tactics they use to do math with superhuman speed. And now, starting today, their success can be your success.

What is remarkable about this system is that it is so simple that even a child can do it. The strategies of these math geniuses can now be duplicated easily by you, giving you the power of using math and numbers in your life. You will enjoy an improved memory and develop a laser-sharp concentration, all while you calculate faster than you ever dreamed possible.

You will not find complicated rules that work for specific situations in this book. Instead, you will learn broad concepts that you can apply to all types of math problems.

You will not find math techniques that will require you to use a paper. After you finish this book, you will start calculating in your head faster than before.

However, for the techniques to become second nature to you, you will have to do the practice exercises that come with the book.

Now, before we go any further, I need to be 100% honest with you. If what you want is a “magic pill” that you can swallow to become a genius (something you already know will never work in practice), then you can stop reading this book right now.

The Ofpad Mental Math System isn't that kind of fantasy land nonsense. It's the real deal, and it is only for folks like you who are serious about improving their intelligence, and who are willing to put in the time to practice to hone this new skill.

While doing math in your head isn't "easy" (nothing worthwhile is). With this book, I have made mental math as easy as it can get.

So, if you're like most folks reading this book, and if you're 100% ready to learn the real secrets of doing mental math faster than a calculator, while increasing concentration, developing better memory habits and learning new ways to think and do math entirely in your head faster than a calculator, then the Ofpad Mental Math System isn't just "A" solution for you. It's the “ONLY” solution for you!

You may think you have seen it all when it comes to math. But trust me you would have never seen anything like this before. This system is entirely different, and it’s nothing like what you have been taught in school. The method I am about to share with you will shock you, and you will be left wondering why nobody ever taught you this when you were young.

Before we get into the actual techniques, I want to tell you about three things.

If you have a question or hit a road block on your journey to master mental math, we don’t want to leave you hanging. We have built a community in Ofpad.com where you can sign-up for free and ask your questions. It doesn’t matter how silly you think your question is, just ask it in ofpad.com/mathqa and we will make sure we answer them. The “Mental Math Q & A Community” chapter will help you sign up to Ofpad and get started in the community, so you can start asking your questions.

The second thing I want to tell you about is learning modalities. People purchase books that they never finish & if they finish it, don’t retain a lot. In spite of all the good intentions, it happens because reading is not their learning modality. I want you to not only learn mental math but also master it. We have created a video course for visual and auditory learners to teach mental math techniques using animations. When they do the math later, they visualise the mental process the same way they see in the video. The entire video course can be watched in a couple of hours, so most people don’t abandon the course half way, like how they do with the book. If you are someone who never finishes a book or if you are someone who learns better when the information is conveyed in visual format, then check out the video course at ofpad.com/mathcourse. If reading is your learning modality then you don’t need the video course and this book is everything you need to master mental math.

Irrespective of the format you choose to learn mental math, remember you are getting the same content. Don’t get the video course expecting content different from the book because you will be disappointed. Pick the medium that best fits you. What is more important is that you MASTER mental math.

The third thing I wanted to mention is practice. Each chapter has an exercise in the end that you must use to practice if you want to master mental math. You can download the rich text PDFs for these exercises from ofpad.com/mathexercises. There is also some bonus email practice that is free for you. Once you finish the book, you will find information to get access to this in the chapter on “Eliminating Skill Atrophy”.

I hope you enjoy learning how to do Mental Math and we can’t wait to hear about your success in the Ofpad community.

 

Chapter 2 - DS Method of Checking

In this chapter, we will cover the DS Method to check your calculation. DS stands for Digit Sum.

This method has been known to mathematicians for several centuries. But it is not widely known or taught in school, which is why it is not used much in everyday life.

You will be able to check the answers of your addition, subtraction, multiplication and division problems quickly using this DS Method. We are covering this first so that you can use it throughout this book.

Rules To Calculate Digit Sum

Rule 1 - Digit sum is simply the sum of all digits in a number.

For example, the digit sum of 213 is 6. You get this by adding 2 + 1 + 3 which gives us 6.

Rule 2 - Digit sum should be a single digit number.

For example, the digit sum of 2134 is 1. You get this by adding 2 + 1 + 3 + 4 which gives us 10. Since a digit sum is a single number we must also add 1 + 0 to get 1.

Rule 3 - You should ignore the number nine when adding across.

Rule 4 - You can also ignore the digits which add up to 9 (e.g. 1 & 8 or 3, 4 & 2). Your digit sum will be the same even if you don’t ignore the numbers that add up to 9.

In 1802, dropping 1 & 8 which adds up to 9 we get the digit sum as 2.

Alternatively, without dropping 1 & 8 which adds up to 9, we will still get the same digit sum 2.

So your digit sum remains the same irrespective of whether or not you drop the numbers that adds up to 9.

It is okay to drop 9 because digit sum will remain unchanged when you add any number to 9. If you see the additions below, the number you add to 9 is the digit sum of the answer....

Table of contents

• Copyright
• Dedication
• Foreword
• Chapter 1 - What Is Ofpad Mental Math System?
• Chapter 2 - DS Method of Checking
• Rules To Calculate Digit Sum
• Rules To Apply DS Method of Checking
• Checking Addition
• Checking Subtraction
• Checking Multiplication
• Checking Division
• Tip – Reduce Running Total to Single Digits
• Limitations of the DS Method
• Summary
• Chapter 3 - DD Method of Checking
• Rule To Apply DD Method of Checking
• Odd & Even Digits in Digit Difference
• Checking Addition
• Checking Subtraction
• Checking Multiplication
• Checking Division
• DS Method VS DD Method
• Chapter 4 - Mental Math Q&A Community
• Chapter 5 - Introduction to Mental Math
• Course Structure
• Defining a Multiplicand & a Multiplier
• Multiplication By 11
• Carrying Over In Mental Math
• Exercises
• Answers
• Chapter 6 - The Inefficient Way to Do Math
• Chapter 7 - Introducing The LR Method
• Chapter 8 - Addition & Subtraction
• LR Addition
• Rounding Up Before Calculating
• LR Addition With Rounding Up
• When Should You Round Up For Addition?
• Addition Exercises
• Addition Answers
• LR Subtraction
• LR Subtraction With Rounding Up
• When Should You Round Up For Subtraction?
• Subtraction Exercises
• Subtraction Answers
• Chapter 9 - Remembering Numbers
• Chapter 10 - LR Multiplication
• One-digit Multiplier
• One-digit Multiplier With Rounding Up
• LR Multiplication – Two Digit Multiplier
• LR Multiplication – Two Digit Multiplier With Round Up
• LR Multiplication After Factoring
• Chapter 11 - Stem Method
• Stem Multiplication
• One-by-One Multiplication
• Learn Multiplication Tables?
• Two-by-Two Multiplication
• Choosing The Stem
• Distance From The Stem
• When to Use Stem Method?
• Chapter 12 - Math Anxiety
• Chapter 13 - Squaring
• Squaring Numbers Ending With 5
• Squaring Any Number
• Exercises
• Answers
• Chapter 14 - The Bridge Method
• Chapter 15 - Vitruvian Man Method
• Chapter 16 - UT Method
• UT Method Concepts
• Practice Exercise
• Pair Products
• Applying UT Method
• Chapter 17 - LR Division
• Definition
• Division Refresher
• LR Division
• LR Division - Factoring
• Divisor Ends With 5
• Factoring Fails with Prime Numbers
• LR Division With Rounding
• Rounding With Reminder
• Combining Methods
• Chapter 18 - FP Division
• Flag & Pole
• Applying Flag Pole Method
• Chapter 19 - Eliminating Skill Atrophy
• Chapter 20 - Conclusion
• About the Author