I'm currently sitting in class while my students are taking their Unit 2 Test on Fraction and Decimal Operations. I can tell that my students would be fine if they never saw another fraction for the rest of their lives, and I can't entirely blame them. Lucky for all of us, we'll get a temporary change of pace with integer operations and exponents in the next few weeks.
Let's revisit the Great Lumber Problem we looked at last week. Since we were looking for 2/3 of 4 1/4, we'd find the answer by multiplying 2/3 x 4 1/4, which is 2 5/6 feet of lumber (or 2 feet and 10 inches - or as Adam put it, 34 inches).
While working on the problem in class, I was surprised by some of the reactions and strategies. I wasn't surprised by the universal instinct to divide. We're cutting the piece of wood, so everyone wanted to subtract or divide. Nobody thought to multiply. This whole idea of the word "of" meaning "multiplying" - even if you're trying to get a smaller number - is an initially strange one, and I distinctly remember the light bulb clicking on sometime in middle school and changing my life forever. It's one of those 7th grade moments that NEEDS to happen, just like the awkward encounters at the dance or the debilitating bouts of acne.
No one knew what lumber was. No one. One student made an attempt, "I drew a piece of string. It's like a piece of string, right?" Wrong. Another was closer, "It's like a big piece of metal." Nope.
Once I opened their eyes to the world of lumber, they thought I was some kind of wooden god. I drew a piece of wood and referred to it as a "2 by 4" and they stopped me. "I thought it was 4 1/4 feet long?" My students might not be picking up on the math, but darned if they don't know a thing or two about lumber now.
"Jeez Mister, how come you know so much about wood?"
Tell them you know so much about wood because you worked at a door factory and if they want to avoid that line of work when they grow up, they better learn how to do fractions. And then treat them to a emotional version of Mahogony and Ruggles.
ReplyDeleteYou know, it's a little sad that a room full of 7th graders is completely unaware of what lumber is.
ReplyDeleteIt's like something I read in the book "Animal, Vegetable, Miracle." I read that most of America's youth are completely in the dark as to where vegetables come from. Most youngsters and a fair number of adults have no idea that their vegetables touch the dirt before they eat them, and probably wouldn't eat them if they knew.
The author of the book mentioned a class of middle schoolers who went to see a working garden, where they were astonished to learn that carrots actually grew underground, and furthermore are actually a root. Their teacher challenged them to think of other vegetables that are roots, and after much thinking and discussion amongst themselves, the students decided that Spaghetti was probably a root as well.
If that wasn't so sad, it would be funny... (and I guess it was still funny because it made me snicker). What else are we forgetting to teach our children? Andy -- I'm so releived you know what lumber is. Wait until these kids see what you know about music! You need to write a song about fractions and bring your digital piano in one day to perform it :) They would never be the same!
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