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25 Comments For This Post

1. ytghanima Says:
   May 26th, 2009 at 5:45 pm

   I, too, think she’s missing the point of the math texts she cites, and suggest watching jamesblackburnlynch’s video response for a strong rebuttal. Just because the traditional methods of learning mathematics are familiar to most parents does not give it validity (women, for instance have “traditionally” struggled with math for decades). I think providing a larger overview of how mathematics works is an element which has been missing from most North American math curriculae, and it shows.

2. BigDickDerrick Says:
   May 26th, 2009 at 5:45 pm

   Nice commas

3. BigDickDerrick Says:
   May 26th, 2009 at 5:45 pm

   This Turk investigations book was really published? WOW.

4. DashingLeech Says:
   May 26th, 2009 at 5:45 pm

   Yes, absolutely. This is basically what I do.

   The benefits of this approach far exceed its efficiency. It is more secure and flexible by aiming for accuracy first and precision second. You can cut if off at the precision you need. The traditional method gives you the most precise digit first.

   In your 26×31 example, we know the answer will be 600 + O(100), so might estimate 700-800. If more is needed, 600+20+180+change, so 800+. If more, 800+6 = 806.

   It’s easier to do in your head too.

5. IXISubzeroIXI Says:
   May 26th, 2009 at 5:45 pm

   I’ve found that both methods take the same amount of time once enough problems have been worked out with each method.

   Being able to do arithmetic fast is vastly inferior to knowing precisely why the answer arrived is correct. And the method I showed in the last post would introduce students to the important properties of the real numbers, namely, the field properties of the reals. Although the “traditional” method should be taught as an alternative, it should NOT be the first method taught.

6. etherealducky Says:
   May 26th, 2009 at 5:45 pm

   the amount of work you have to do compared to the traditional method much more.
   when i was learning this stuff i had to do it fast. if i had to learn this way there is no way i could have done it fast. i would have been sitting there for at least a minute trying to figure it out.

7. Kinokarte Says:
   May 26th, 2009 at 5:45 pm

   Some of those alternative algorithms basically work by subdividing the problem into more, but simpler steps - that’s basically an adjustment for lower IQ people.
   Then there were those methods of “just trying around” without thinking… seems fitting that this is taught in the U.S.

8. IXISubzeroIXI Says:
   May 26th, 2009 at 5:45 pm

   I really don’t understand why people use the “traditional method” or the other strange methods of multiplication. As a math major, I’ve come to rely on the following fail-proof method of multiplication:
   26×31 = (20+6) x (30+1)
   (20×30) + (20×1) + (6×30) + (6×1)

   It’s computationally efficient and doesn’t involve the strange notion of “carrying” digits. It’s also much more geometrically intuitive: this represents the notion of adding up smaller rectangles to find the area of the larger rectangle.

9. kkjsoerensen Says:
   May 26th, 2009 at 5:45 pm

   I think my brain just stopped working

10. sleeper2345 Says:
    May 26th, 2009 at 5:45 pm

    Just because she can do it, it doesn’t mean she understands why this method works. Can she draw an array using an area model? Does she see the connection between this and (x+3)(x+3)? I don’t think so based on her statements. Carrying out a procedure does not mean someone has a deep understanding of the underlying mathematical ideas.

11. carrythefifth Says:
    May 26th, 2009 at 5:45 pm

    She understands the partial products method, she just said it was error-prone and not very efficient.

    If you’re multiplying numbers into the 1000’s with that method, you’ll have numbers all over the place. It would be easy to mess up.

12. zgates Says:
    May 26th, 2009 at 5:45 pm

    Your points contradict each other, though. If it’s pointless to know how to multiply, then knowing why is even LESS useful. Thus in the age of calculators, what works best is the most efficient, if for no other reason than it means kids will be reaching for their calculators less often if it’s faster to quickly write it out.

13. wurlybird9 Says:
    May 26th, 2009 at 5:45 pm

    one must develop a thorough understanding of the foundations upon which they build

14. Paradise737 Says:
    May 26th, 2009 at 5:45 pm

    I can kind of understand what Everyday Math is thinking.

    The traditional algorithms might be the most efficient, but kids don’t really understand why they work. Furthermore, once you hit middle and high school, you start working with calculators, making pointless the knowledge of how to do multiplication. Everyday Math’s method makes you work with numbers in your head and understand where the answer comes from, which I do think is helpful.

15. sleeper2345 Says:
    May 26th, 2009 at 5:45 pm

    I work with college students who don’t understand the traditional algorithm all the time. I guess it doesn’t make any difference what method is taught is students don’t follow it. Note, too that McDermott in the video doesn’t understand why the traditional algorithm works. If she did, she would understand the partial products method.

16. qwertyxuiop Says:
    May 26th, 2009 at 5:45 pm

    I work with students in a Seattle high school. One of them did a multiplication problem using the lattice method recently. The poor 9th grader has no idea why it works and it takes her forever to draw the darn box. Now I see where it comes from. I also find it somewhat humorous that the Everyday Math authors find standard algorithms a waste of time. All of their little tricks are a waste of time designed to mask their one big failing: students can’t do ANY basic arithmetic.

17. honeybbqgrundle Says:
    May 26th, 2009 at 5:45 pm

    English is probably not your primary language, but if you watch again you’ll realize that she is NOT a math professor. Her job has nothing to do with mathematics (somebody else has already done that part for her).

18. eboyzki Says:
    May 26th, 2009 at 5:45 pm

    thank you for theis video. i don’t think those everyday math methods would even help the society. man, mathematicians must be REALLY bored to come up with such stuff.

19. Meowth9000 Says:
    May 26th, 2009 at 5:45 pm

    It is a good video. You learn something at least.
    She probably did help lots of people. She’s a proffessor of Math.

20. Meowth9000 Says:
    May 26th, 2009 at 5:45 pm

    Using a Calculator doesn’t help at all. You wont know how to do the math if you use Calculator’s.
    You have to try memorize some stuff. But you cant memorize evrything.

    School Teachers have been very harsh with “memorizing”
    They force the students to memorize everything. Which in my opinion, is horrible. We should only memorize occasionally.

    They also force us to do the math in the way they tell us to do. But were all different, so we should do the math on what way we solve the math to answer.

21. egyptiansushi Says:
    May 26th, 2009 at 5:45 pm

    This video was insanely interesting considering its content. :]

22. Meowth9000 Says:
    May 26th, 2009 at 5:45 pm

    This is a very interesting video. I have a very high interest in Education.
    I like books though. They make you understand more words. It also has been proven that it can help you in education.

    By the way. Math is a very interesting subject. I hope I can one day become a Math Teacher.

23. goodgood199 Says:
    May 26th, 2009 at 5:45 pm

    I can multiply three digit numbers in my head with the cluster method so stfu stupid mj

24. unarmed1234 Says:
    May 26th, 2009 at 5:45 pm

    use a calculator… lol

25. nickolayer Says:
    May 26th, 2009 at 5:45 pm

    Exactly!
    You’ll want the standard algorithm for numbers with over three digits; that’s something our memory usually can’t tackle.
    However, instead of grasping your pencil and writing all these digits, you can use the cluster method for smaller numbers and produce lightning-fast answers.
    To tell the truth, I didn’t even know it was called “cluster method”)

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