Thu 8 Dec 2005
Brain Freeze (and not the good kind involving ice cream)
Posted by cindy under Uncategorized at 4:23 pm[15] Comments
I was helping Mr. W’s daughter with her math homework yesterday, and I use the word “helping” very, very loosely. People who know me know I avoid math whenever possible, and in college, I’d taken anything that would fulfill the same credit requirement that math would — geology, pollution & atmospheric sciences, accounting, oceanography — to avoid taking a math class. (I must’ve been out of my mind to take AP Calculus my senior year in high school.)
My brain froze on this equation:
A train leaves the station traveling 45 kilometers per hour going east. 3 hours later, a second train leaves the same station and travels east on a parallel track at 68 kilometers per hour. How long would it take the second train to catch up to the first train?
WHO REMEMBERS HOW TO DO THAT?! I mean, I could probably do it the dummy way and make a chart of “hour 1, train 1 is this far away. hour 2…” and then do another series for train 2 and wait for the numbers to coincide. But apparently this is a distance = rate X time algebraic equation set-up thing.
BLEAH! *vomit*
haha…that sounds so familiar…
What sounds familiar? The type of equation, or my bitching about math?
What class did you do this equation in? Was it a college class? Cuz it seems awfully complicated for high school Algebra I. Another equation she had contained elements like “You’re paddling a canoe upstream, against a current of 12 kilometers per hour”…”you then turn and go downstream…” The the question has something to do with how long it takes you to paddle the trip or something like that. They may have also given the total paddled mileage upstream, I’m not sure. I’m like, “Isn’t that PHYSICS?!” Cuz you gotta figure resistance, how fast you’re paddling despite the currents, etc.
sounds like stuff i did in middle school! i love math.
ARE YOU JUST RUBBING THAT IN?!
I think that was one of those cross multiply situations where you put 45/x = 68/x+3 where x is time and you end up with x (time) = approx. 5.87 hours.
Of course, I finished high school math not quite as long ago as you did, so I think it’s just fresher in my mind.
Funny thing is, I don’t even think I completely understand why that equation works.
uh… what?
The trains meet after Train 2 has been traveling at a rate of 68 km/h for t hours (the amount it takes “to catch up�)
Distance = rate x time, so D2 = 68t.
At the meeting, Train 1 will have been traveling at a rate of 45 km/h for (t + 3) hours (i.e., three hours longer than Train 2)
Distance = rate x time, so D1 = 45(t + 3)
Since the trains meet, they must have traveled the same distance, so D2 = D1.
Therefore, 68t (=D2) is equal to 45(t + 3) (=D1)
i.e.,
68t = 45(t + 3)
68t = 45t + 135(multiply out of the parentheses)
23t = 135 (subtract 45t from both sides)
t = 5.87 (divide both sides by 23)
That took a lot of concentration and forcing myself to not look away, but Adam, that made perfect sense. That’s why they extended the Mensa membership to you. I had pieces of that logic in my brain when I was trying to set up the equation, but I just did not have it all there, my brain kept shutting down in the middle of a train of thought, no pun intended. Or as Calvin (of Calvin & Hobbes) would say, my train of thought was still boarding at the station. The shortcut my cousin Mark did, however, was not immediately clear to me.
I hope to never have to squint, frown and drool at an equation like that again.
I’d guess you jumped into the “algebraic equation set-up thing” mode too early.
Word problems invoke a different kind of thought process than straight mathematics does–conceptualization rather than calculation. When you sit down to a math problem your brain goes into “calculation” mode. It’s hard to know when to conceptualize first.
It’s so nice of you to say things like that, Adam, instead of saying what you’re really thinking: “You’re stupid.” Yeah, I know, I know you well.
I wasn’t thinking that. Tell you what I was thinking, though. I cringe at the thought of you teaching math to a young girl.
Young people can get it into their minds early that they belong in one box or another. “I can’t do math.” “I can’t sing.” “I’m a slow reader.” “I’m not good at writing.” “I’m left-brain, not right-brain.” “I avoid math whenever possible.”
It’s limiting and it’s crap.
A young girl doesn’t need a beautiful hero-woman telling her, with charm and humor, that beautiful hero-women don’t do math. (And I know what you’re thinking, but telling her some of your best, most beautifulest female friends do math doesn’t cut it.)
I applaud your helping her with her math. Make sure you approach it enthusiastically, not dismissively. Now, go out and get the book and keep one chapter ahead.
Thank you for your (backhanded) compliments. I’m not regularly helping her with math, but she was frustrated enough that evening to call out for help. I never told her I “don’t do math,” what I said was that I was rusty and lemme see if I can remember how to do what she was on. I figured the first one out, set up the equation, explained it to her, she did it right (I thought) but the answer didn’t plug back in correctly, so I did it myself and found her calculation error, and explained it to her. The one I got stuck on, luckily she figured out on her own.
As much as I may whine and cry about how I can’t do math to you and my other peers, the reality is that I’m rusty as heck on Calculus and Physics equations, I dislike the proofs in Geometry and the circular graph things in Trigonometry, but I have consistently tested extremely balanced in my logic and creativity, something like 51% left-brained, 49% right-brained. I am well aware that I CAN do math if I bothered to refresh my skills those directions (which I don’t want to).
Thanks for the reminder about limiting youngun’s subject to influence.
Hmm. That doesn’t read the way I wanted it to. What I mean is, I hope that not only do you not tell the girl your funny (I laughed) jokes about drooling over math problems, but you go overboard the other way–tell her how wonderful math is and that you believe she can be a physicist or engineer if she wants.
Because believing you’re good in math is the first step on your way to law school, where all people of good heart long to go.
She aspires toward the performance arts, and does well in English. But I have told her that advancement in math through all 4 years in high school is a prerequisite to getting acceptance to UCLA, where she wants to go. (Yay for future Bruins!) Her good heart does not appear to have any room in it for Law.
high school algebra class, i think.