We're into high school algebra here at our house. It's so much fun. It brings back such great memories. Problems such as this:
A snail was chasing a worm. The worm (at 2"/sec) had a 75 second head start. The snail was really full of caffeine and was really moving at 5"/sec. How long until the snail catches the worm?
Oh the dreaded word problems. These are supposed to be the best way to prepare kids for real life math. And, I guess it does. At least this book takes a more creative approach. I remember doing these types of problems in school and hating them. I never quite got it.
Brianna had this last problem, plus a couple of others, on her last math test. She missed them. I sat down with her trying to figure it out and couldn't. I asked Brian to help her figure it out and he couldn't. The next step was to give the author a call and have him explain to her how to figure it out. I decided to give it one more try last night. He did explain earlier in the chapter how to figure out a problem like this. If two adults and one student can't figure it out, what would that equal?
I read slowly, I transferred the numbers from this problem into the example. And, I figured that thing out! Considering that I did this after my 6th day of work while sitting with a beer at 9:00 at night, I think that's pretty good!
Here's parenting tip #503 - Before your kid gets to middle school math, go back to community college and take some math classes. Not only will you be able to help your kids when they get to middle school and high school level math, but you will feel like you own those math problems! And, by this age, your kids may just think that you actually know something.
**Here's my challenge to you...
Do you know how to figure out the snail/worm word problem? If you can give me the answer by Monday night, I'll send you some cute knitted coasters!
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7 comments:
Yes!
You set up the equation like this:
2"/sec times 75 sec + 2"/sec times x sec = 5"/sec times x
Which in math looks more like this
150 + 2x = 5x
x = 50
The snail will catch the worm after 50 seconds.
Luke - you did that all too quickly. I guess some people are born with the gift of math.
boo, Luke. you beat me to it!
and it definitely took my brain a couple of tries to actually set up the equation right. which is embarrassing given that I spent all of last year tutoring algebra.
The worm's equation of motion would be: 2t + 75 where t is equal to time in seconds.
The snail's equation of motion is simply: 5t
If you could visualize both of those equations as lines and you're interested in where the two lines intersect... put another way, you're interested in solving for t in this equation:
2t + 75 = 5t
75 = 5t - 2t
75 = t(5 - 2)
75 = 3t
75 / 3 = t
t = 25
In english: the time at which the two line intersect is 25 seconds. And for bonus points you could determine how far along they are in distance by feeding the time back into one of the equations... take your pick:
snail's for example: 5 X 25 = 125 inches
worm's: 2 X 25 + 75 = 125 inches
I got a different answer and I cheated because I asked Chris :)
HAHA he just re-did itThat's 50 seconds, 250 inches.
I love how a math problem and a giveaway for knitted coasters brought out the lurkers! ;-)
Hey those coasters came really fast! Thank you!
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