This post is part of a four-part series called, The Three Books Needed to Shatter School. If you haven’t read the first post, click here!
3. Secrets of Mental Mathematics
What a post I have ahead of me! I have accomplished some seriously ridiculous things with this book (like doing five-digit squares in my head)! Studying mental math caused me to find even more reasons to love math. However, before I talk about what I like in this book (and other mental math books in a future post), I will first talk about what I oppose or dislike in this book.
Alright, now that I have thoroughly dealt with things that can lead others down a wrong path, lets talk about the math and the exciting things in this book!!! Math is so awesome on such a variety of levels. I have read many mental math books, and I like the techniques in this one a lot.
It talks about two things in a very well done manner: an in-depth approach at left to right arithmetic and a special way to do squares that isn’t specific to different types of numbers. For instance, it is a lot easier to do 246+397 if you do it this way: 397+200=597, 597+40=637, 637+6=643! Of course in this case it would be much easier to do 246+(400-3).
I won’t go too in-depth with squaring numbers, but this book shows you how to take something as daunting as 47^2, and turn it into something as easy as (40*54) + 49, which is only the beginning! I have studied a lot of mental math books, and I have learned that there really is something amazing to knowing algebra and doing arithmetic. The problem seems too hard? Rearrange it with algebra!
I have two last things to share: cool biographies that this book includes, and things I have been able to do with the techniques in this book. Exciting stories of people like Gauss and Zerah Colburn are mentioned in this book. You’ll just have to read all about it! Lastly, as I mentioned before, I have done 2,3,4, and 5 digit squares in my head; I have done addition, subtraction, and division in my head faster than someone could get a calculator; and much more is on the way! I am going to finish reading Trachtenberg’s Speed System of Basic Mathematics book which allegedly teaches you to do nine digit square roots in your head! Until next time!
Yours most respectfully,