Lattice Multiplication

Discussion in 'Debate & Marathon Threads Archive' started by Aliceacc, Sep 19, 2013.

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  1. Aliceacc

    Aliceacc Multitudinous

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    AAACCCKKKK!!!!!

    Where's the smiley for "I want to pull my hair out because this cutesy little trick annoys me so much"????

    Anytime I have had a kid try to use it, the answer has been wrong. They don't remember the process, and since it makes no sense to them, they can't figure it out.

    It cost one of my kids some unnecessary points on Tuesday's test. Now I'm going to have to teach an Honors high school freshman how to do basic multiplication the real way.
     
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  3. muinteoir

    muinteoir Companion

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    I don't know what lattice multiplication is, but the math teacher on my team was saying exactly the same the other day.
     
  4. Upsadaisy

    Upsadaisy Moderator

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    Makes me nuts, too.
     
  5. a2z

    a2z Virtuoso

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    Isn't it amazing how something that has worked for such a long time can be replaced by something that someone else makes up because they didn't quite understand the original way or wanted to make their mark. So, they create something that works that is so convoluted almost no one understands it and then market's the heck out of it until a bunch of educators think it is "cool" and "new" and something that will change the place of the "old" and "boring" that really worked well.
     
  6. Upsadaisy

    Upsadaisy Moderator

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    You said that so well! Some things are better left alone.
     
  7. DizneeTeachR

    DizneeTeachR Virtuoso

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    I know when I tutored some family I always told them math was about finding the "trick" that worked for them!!!
     
  8. MissCeliaB

    MissCeliaB Aficionado

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    In my math ed courses, we were told to introduce it to students as an alternate algorithm. A very few kids may find it easier, but many would not. Our instructor also recommended not to teach it until the 5th grade or so, because in her experience most students younger than that lack the motor skills to draw the lattice correctly in the first place! She felt it should be shown as a neat trick, not the new way to do math.
     
  9. mmswm

    mmswm Moderator

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    The time would be better spent teaching struggling students WHY the traditional algorithm works rather than coming up with some convoluted "alternative" that really is no alternative at all and gives them nothing to build on when they get to more complicated concepts in higher level math classes.
     
  10. bison

    bison Habitué

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    Ugh, I hate this one as well. I love for kids to have options when it comes to math, but lattice multiplication has ALWAYS been more of a hindrance than a help for students I've worked with! The few that do well with it aren't the ones that need an alternative method anyway.
     
  11. Jerseygirlteach

    Jerseygirlteach Groupie

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    I've never even attempted to teach it and I've given students multiple methods and memory tricks for multiplication. It just seems way too confusing.
     
  12. MsMar

    MsMar Fanatic

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    I am so glad I've never had to teach it nor have any of my children have had to learn it. It's so stupid. And it doesn't help at all with actually understanding multiplication.
     
  13. RadiantBerg

    RadiantBerg Cohort

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    One of my colleagues teaches a similar strange method for factoring polynomials involving boxes. It confuses me.
     
  14. Aliceacc

    Aliceacc Multitudinous

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    If it's the same version my friend uses, it's a variation on the "eyeglass method" of factoring polynomials with a leading coefficient greater than one. You break down the 1st degree term and use factoring by grouping.

    It's not always faster than trial and error, but it's a good process to teach kids who NEED a real process in order to factor.
     
  15. RadiantBerg

    RadiantBerg Cohort

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    Yes, I do show them how to do the grouping--I call it the AC method, but I don't add the box components. The only thing that drives me crazy is when they use this long procedure to factor a polynomial when a=1. I mean, it works, but it's like using a sledgehammer to kill a mosquito....and they usually make errors.
     
  16. Melanie Therese

    Melanie Therese Rookie

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    I just looked this up and it's crazy. What's wrong with just multiplying the numbers? It's a neat trick, but making it your primary way of doing this is nuts. So, basically, solidarity!
     
  17. MissScrimmage

    MissScrimmage Aficionado

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    I had to Google it and I'm not sure I could teach kids how to do that. It makes sense, but they would have to be pretty organized to keep everything straight in their notebooks.
     
  18. ready2learn

    ready2learn Comrade

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    It drives me crazy looking over lattice multiplication to try to find student's mistakes.

    What drives me more crazy than lattice multiplication is that my students do division with partial sums. This makes division of decimals interesting.
     
  19. ecteach

    ecteach Devotee

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    I LOVE IT, but I am horrible at math. Maybe it would just be a good strategy to teach those who are struggling with the "regular" way.
     
  20. mmswm

    mmswm Moderator

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    And set them up for a cycle of failure? I don't think that's a good idea.

    It's a parlor trick that's long, confusing, prone to error and does absolutely nothing to help students succeed in the long run.
     
  21. a2z

    a2z Virtuoso

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    When it comes to math, strategies to get around difficulties is not always the best approach, especially if that strategy is cumbersome, prone to error, and doesn't really have anything to do with math. You would be better off using the strategy of the calculator.
     
  22. yellowdaisies

    yellowdaisies Fanatic

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    I had to Google it...wow. How would that be easier than the regular way? That is just super confusing to me.
     
  23. RadiantBerg

    RadiantBerg Cohort

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    I agree that I would sooner just let them use a calculator than teach them this trick.
     
  24. ecteach

    ecteach Devotee

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    It works for me every time I use it.
     
  25. mmswm

    mmswm Moderator

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    Parlor tricks work every time too, so long as the person performing the trick has rehearsed them enough.
     
  26. ecteach

    ecteach Devotee

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    Such strong feelings about lattice multiplication. lol...

    I mean, it is what it is, right? Are you required to teach it?
     
  27. waterfall

    waterfall Virtuoso

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    Doesn't Every Day Math teach lattice? In my first school all of the gen ed kids were taught it so that's why I'm making that assumption. I used to work an after school homework/enrichment club and I couldn't help them with it because I did not understand it at all! The SLP worked with me after school and we sat there for 20 minutes one day trying to figure out how it worked. I taught my kids in sped the regular way and they picked it up fairly quickly. I will say that I was assessing one of my 5th graders for new IEP goals the other day and I was shocked at how quickly and accurately he was solving multiplication problems...and he was using lattice. He then proceeded to some lattice-type thing with division (never seen that before) and he was solving those correctly too. For being on a math IEP and in the second week of 5th gradeI think that's pretty darn good. Obviously it works for him.
     
  28. mmswm

    mmswm Moderator

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    Well, since I feel that not only does it not do any good, but causes actual harm, yes, I do feel strongly about it. It's a grave disservice to a student's future ability to learn higher topics in mathematics.

    As Alice's first post pointed out, she had to waste time at the high school level teaching something a student should have learned in elementary school in order for him to learn the topics she needed to teach. Why should either Alice or her student have had to go through that?

    Instead of teaching cute tricks, time would be better spent teaching real math.
     
  29. gr3teacher

    gr3teacher Phenom

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    I'm surprised to see the hate for the lattice method here. When you break it down to a conceptual level, I think the lattice method makes a lot more sense than the traditional algorithm. I don't think it should just be handed to students, I think it requires them to get where it comes from, but it's hardly a "parlor trick." It's a way to get them to actually see all the neat place value things that are actually going on with multiple-digit by multiple-digit multiplication.
     
  30. ecteach

    ecteach Devotee

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    Point valid. This is probably a really ignorant question, but how would teaching multiplication this way hinder a child from learning higher level math? I really don't know. I am not trying to cause an argument or be a smart a**.
     
  31. teacherintexas

    teacherintexas Maven

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    I've never taught it, but I did get yelled at for teaching the area model in addition to traditional two digit by one digit multiplication.
     
  32. gr3teacher

    gr3teacher Phenom

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    Wow... I can't even imagine trying to show my third graders the traditional algorithm without showing them the area model first. That would be like teaching kids to add without ever giving them manipulatives to practice with.
     
  33. teacherintexas

    teacherintexas Maven

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    I know! That's why I'm still going to teach that, whether the upper grades like it or not.
     
  34. czacza

    czacza Multitudinous

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    I think it's cool, but don't teach it.
     
  35. karebear76

    karebear76 Habitué

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    I teach it to my students. It gets them multiplying larger numbers when they cannot use the traditional algorithm due to regrouping errors. I can move them forward with lattice, or we can stay on regrouping lessons for the entire school year.

    My math methods professor taught it as an acceptable algorithm. I'm far from a mathematician, but I'm having a hard time comprehending the hatred expressed here.
     
  36. readingrules12

    readingrules12 Aficionado

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    I've seen Lattice multiplication for about 20 years. I even used it as an alternative one year. I no longer have anything to do with it. The largest problem I see (that other posts also state) is that the students forget these steps very quickly.

    I think it is time to pull the plug on Lattice multiplication.
     
  37. mmswm

    mmswm Moderator

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    Our job as teachers is twofold.

    1) Teach the concepts at hand
    2) Provide the students a foundation in which to expand on prior knowledge when necessary.

    Lattice fails miserably on that second part.
     
  38. gr3teacher

    gr3teacher Phenom

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    Repeating "Cheap parlor trick" over and over doesn't make it true, and being insulting isn't going to make me change my opinion.

    Again, if you just hand the lattice method to students, that is a mistake. If you show them that it's ultimately a quicker version of the area model, and show them the way places line up, they'll have a better conceptual understanding of the process when they ARE ready for the traditional algorithm... because to put it bluntly, students are ready to handle 2-digit by 2-digit multiplication before they are ready to handle the traditional algorithm.
     
  39. JustMe

    JustMe Virtuoso

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    I don't think it's fair to accuse a teacher of not caring because he or she teaches this method. Some students can benefit from these interesting "parlor tricks". As someone who struggled severely in math, sometimes the strangest way of working with something clicked for me. I'm not proposing it be taught in place of regular multiplication, but it's a method to keep handy for those struggling as it just might work.

    ETA: Refers to a post that has been deleted.
     
  40. mmswm

    mmswm Moderator

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    Believe what you will. In the end, it's the secondary teachers and your students who have to suffer from your unwillingness to listen to actual mathematicians.

    The bottom line is that you are harming your students in the long run. If you're okay with that, keep doing it. I'm done wasting my time.
     
  41. gr3teacher

    gr3teacher Phenom

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    Considering that 100% of my students have progressed to the traditional algorithm when they were ready for it (usually within a matter of a few days of learning nontraditional algorithms), rather than being immediately force fed a method they aren't prepared to handle, don't have a conceptual understanding of and thus aren't successful, I think I'll go ahead and keep doing what I'm doing, if it's all the same to you.
     
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