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80 of 86 people found the following review helpful:
5.0 out of 5 stars
Reply By The Author, April 22, 2005
This review is from: Speed Mathematics: Secret Skills for Quick Calculation (Paperback)
A farmer told me, Your methods don't help me milk the cows. He was right, and his comments were about as relevant as the two reviews by people who haven't read my book.
Firstly, Trachtenberg's book was criticised for similar reasons forty years ago. I was a fan of Trachtenberg and thought that the criticism was unfair because the critics had misunderstood the purpose of the book. The book was discarded by the critics as discredited. It was still read, and inspired a love for mathematics in many who went on to make their career in education or professions requiring mathematics.
My critic states he has not read my book and then says my book doesn't teach how to multiply large numbers mentally. It does. It teaches the same method as Trachtenberg. We both got our method from the same source. My book does not teach the two-finger method of multiplication. I have never liked it.
My book begins with a method for multiplying one and two-digit numbers. Using the method, children master their multiplication tables in minutes. Instead of being difficult to remember, and a disaster, very young children use the method to master their multiplication tables and learn their basic number facts in record time. Educational authorities and faculties of education in many universities around the world are recommending my books and my methods.
My critic states I don't explain the simple algebraic formula behind my methods. I do. This is the problem with criticising a book you haven't read. In fact, I give several explanations that can be understood by fourth grade students.
Trachtenberg teaches a separate formula for multiplication by each number up to twelve, each involving several steps. They are difficult to learn and to remember. I teach one simple formula that allows anyone to instantly master his or her tables up to the twenty times table and beyond.
My methods for long division and for finding square roots are also much easier to master than Trachtenberg's.
I do not mind criticism, but I like it to be fair and accurate. I have taught the methods around the world, taught thousands of teachers and student teachers, and hundreds of thousands of students. I have received a lot of feedback from students who tell me they are using the methods successfully in the classroom, and from technicians and engineers who are showing off on the job. Teachers of primary (elementary) school children tell me the children ask if they can do mathematics for the rest of the day. This is unheard of.
I have emails from professors of mathematics, from engineers and engineering students as well as young children, who tell me the book has opened up new horizons for them. No one has written that he or she found the methods difficult or the steps difficult to memorise. As you read the explanations in order you find it makes sense and there is no difficulty.
My critic's biggest mistake was that he did not understand the purpose of the book. It was not meant to teach anyone to milk their cows. Nor was the purpose to enable people to multiply six-digit numbers by five-digit numbers mentally, although it does teach this if you want to do it. The purpose is to teach an easy way to solve mathematical problems and to give an understanding of the basics of mathematics. I have plenty of email from children who found the methods easy, and it is interesting that students who excel at mathematics love the methods as well as the students who have believed they are mathematically hopeless. One benefit of the book is it not only teaches you how to solve problems, but it also teaches you what you say in your head to solve them.
Read the book for yourself and make up your own mind.
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53 of 57 people found the following review helpful:
3.0 out of 5 stars
A LONG COMPLICATED REVIEW, December 10, 2003
This review is from: Speed Mathematics: Secret Skills for Quick Calculation (Paperback)
The classic book on high speed calculation was written by Lester Meyers and titled HIGH SPEED MATH SELF-TAUGHT. I have two copies of the 1961 edition on my paperback shelf since I pick up a copy anytime I see one at a library sale. I got my first copy in sixth grade (true story). There are very few tricks that appear in ANY speed math book that don't also appear in Meyers book. But most of Meyers book is information on what to do in very specific problems (multiplying by 9, multiplying by 36, etc.) Nowadays, people generally want methods that are applicable in a wide variety of situations, not just multiplying by specific numbers.
A good test for one of these books is to see how it deals with division. Division is by far the most difficult operation for kids to learn, and books on speed math are often very short on division methods. Handley's book contains two methods, one of which, as far as I know, only appeared in A. H. Russell's RAPID CALCULATIONS (printed in London, 1956, hard to find.)
Why three stars? The book is very good in teaching what Handley calls the reference number method for multiplication. But I think the average reader would have difficulty following some of the explanations for both division methods. Handley's subtraction method (which he says he was taught in third grade) is excellent - recommended for any parent whose kids are having trouble borrowing. There are other interesting things here(meaning things I have not seen before or not seen in awhile)--an easy way to go from Fanrenheit to Celsius or vice versa, multiplying feet and inches by feet and inches, a quick method for mental square root estimates. But I am not sure the average reader will be able to follow all of Handley's explanations. So, next reviewer, whoever you are, please comment on how easy to follow you found the explanations to be. Maybe I am unnecessarily pessimistic. In any case, despite these reservations, the book is recommended.
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10 of 12 people found the following review helpful:
5.0 out of 5 stars
Regarding 13*54, October 5, 2005
This review is from: Speed Mathematics: Secret Skills for Quick Calculation (Paperback)
First, a great book. I'm enjoying putting some of these methods to use!
Second, in response to Nehal from 4/7/05:
"But what happens when we want to multiply 13 x 54? In this case, we would like to start out with 10 (for 13) and 50 (for 54) giving us 10 x 50 = 500. In other words, we use 2 Reference Numbers: 10 and 50. Next, we make the corrections from here."
13*54
Use 10 as the reference number for both. Mentally write
+3 +44
over the 13 and 54 respectively.
Gives
54 + 3 = 57, and 57 * 10 = 570
so 570 +
44 * 3 = 120 + 12 = 132
so the answer to 13*54 = 570 + 100 + 32 = 670 + 30 + 2 = 702
Sure, problems in general get more difficult as you stray from the reference number, that's a given, but it is no big deal.
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