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Friday, April 25, 2008

a Math Trailblazers word problem

Lefty's post about the new research on word problems comes just two days after I found this word problem in a 5th grade Trailblazers homework pack:

Lee Yah and Manny are setting up tables for the 5th-grade family craft show. Each table is 200 cm long. Tables will line up along 2 sides of the room which measures 12 meters each. [could I possibly have copied this sentence correctly??] Each participant who wishes to sell crafts pays a $15 rental fee for 1 table or $25 for 2 tables. Mr. Moreno tells the students that all tables have been rented. Only 2 people rented two tables. How much money will the school make on the craft show?

The first thought that sprang to mind when I read through this problem was: no child can possibly learn math from this.

I myself find the thing close to inscrutable. (Do the same people who write instruction manuals write word problems for Trailblazers?)

fyi: one of ktm's frequent commenters sent me this observation in an email just last week:

But what I have long worried about is that for some reason, the skills taught in reform math programs do not *transfer* well. I have never seen anyone talk about that, but I've seen it time and again. Their learning seems to be really confined to the particular context/problem they learned it in.

Query: Does teaching new concepts in a "real world context" have the inadvertant effect of obstructing the transfer of that learning to other contexts? Do kids who learn things in the abstract have an easier time of it?

I get $170.

11 comments:

  1. I can't resist a good math problem. Unfortunately, this isn't one.

    My first thought upon reading the problem was, "But how WIDE are the tables?" Because, of course, I was thinking that lining up tables along two sides of the room, you would choose two sides that join at a corner, and the table width is important to know in figuring out how much dead space is taken up in the corner, so you'd know how many tables you could fit in the room.

    But no.

    FWIW, I also get $170. 12 tables; 4 tables @ $25 per two tables, 8 tables @ $15 per one table. 4T * $25/2T + 8T * $15/1T = $170.

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  2. oh brother

    at first I thought the whole damn problem was a red herring -- the only real info was that 2 people had rented 2 tables (and was that 2 apiece or just each person rented 1)...then I forced myself to read WORD BY WORD AND LINE BY LINE & discovered that all the rest of the gunk applied....

    this is wretched

    and so badly written

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  3. My son and a few friends rented a table at a school craft fair once and there was space between the tables so that the people selling could get behind the table. That was my first thought. One might say, however, that figuring out what to do with poorly-defined questions is a good skill to develop.


    Outside of the issue of figuring out how many tables there are, it's not a difficult problem, and you can't really say that this problem belongs to a curriculum that teaches new concepts in a real world context. You have to see how the kids were prepared beforehand.

    However, reform math techniques do not transfer well because they try to develop magic thinking skills which may or may not work on other problems. Change one thing and you might get stuck. It's anti-math. Math is all about mastering techniques or tools that allow you to solve problems without a lot of thought and you know that they will be correct.

    For example, if you aren't sure how to solve a particular problem, draw a picture and define some variables. Start writing equations. If you get enough (independent) equations, then you turn the crank and solve the problem. You barely have to think.


    I think their idea is that if you struggle with solving something (without much background skills), you will understand the basic skills more. Unfortunately, there is not enough time and importance placed on making sure that mastery of the basics gets done. They hide behind their magic thinking skills.

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  4. So the first sentence provides no information, but confuses you as to who is doing what and what for (do you need to know how to set the tables up? Are there two people or three setting them up? etc.)

    The second sentence provides a fact in units that are ridiculous.

    The third sentence is grammatically incorrect and visually unclear--are the sides touching? do you need to worry about how the tables overlap?

    The next sentence provides a fact but adds useless data.

    The next sentence adds new characters to obscure a fact.

    The next sentence is grammatically unclear, and tells a fact in an unclear way: 2 DIFFERENT people rented 2 two tables each? Or a couple rented "two tables" ?

    Do people who write these things ever DO the math problems themselves, do you think?

    And what, precisely, was the point of the problem? unit conversion? an simple algebraic manipulation? Proper use of the associative property?

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  5. Forgive the person who's formal math education ended in Grade 11 but I would think that a good word problem should reflect how a person with reasonable good thinking skills would put together that problem in their mind. Short and sweet, like the Singapore stuff.

    If I were standing in the room where those tables were set up there's no way I'd construct that paragraph.

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  6. "If I were standing in the room where those tables were set up there's no way I'd construct that paragraph."

    That's a good way to put it.

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  7. One of the things that is exceptional with Singapore Math is that the questions are always crisp, focused on the math, and challenging mathematically.

    I actually had to sit through a meeting once with a consultant who harangued us about not using the pictures in the math book enough to 'connect to the children'. Clueless!

    Another told me there wasn't enough love in my classroom. I had her model the love for me a few weeks later and the kids were actually throwing stuff at her by the end of the love in.

    She left the room and handed it back to loveless moi on the way out the door. Sighhhh...

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  8. Another told me there wasn't enough love in my classroom. I had her model the love for me a few weeks later and the kids were actually throwing stuff at her by the end of the love in.

    You're kidding!!!!

    What happened!???

    You can't just leave us hanging like this!

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  9. There is a serious love shortage around these parts.

    Let me tell you.

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  10. They absolutely believe struggle = comprehension. It's a eureka moment theory of instruction.

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