G'w'uh?

tarnok

Diabloii.Net Member
G'w'uh?

I'm confused. Perplexed. Puzzled even.

I just started grading my first set of papers and one of my students presents the most amazing conundrum. He sets up the problem correctly. Simplifies it and isolates the variable correctly. Reduces it to the point where all that is required is simple division which is easily accomplished either by hand or with a calculator, and then gets the wrong answer.

An example. The last line of one of his problems reads: 120/600 = 72000. There was a decimal point in there somewhere, but the marks he made in attempting to convert it to a percentage make it impossible to tell where the decimal point originally was. Notwithstanding, that's nowhere near the correct answer of .2 no matter where you place the decimal point. Most of you have probably noticed by now that if you divide 120 by 600 you get the correct answer, but he apparently decided on some other operation which I still can't fath... oh dear God. He added them together.

I'm no longer puzzled, but I kind of wish I were. I think this boy may need to review basic arithmetic.

Edit: No, I'm still puzzled. Not all of them were added together and I can't figure out what he did to some of them.
 

maccool

Diabloii.Net Member
tarnok said:
An example. The last line of one of his problems reads: 120/600 = 72000. There was a decimal point in there somewhere, but the marks he made in attempting to convert it to a percentage make it impossible to tell where the decimal point originally was. Notwithstanding, that's nowhere near the correct answer of .2 no matter where you place the decimal point. Most of you have probably noticed by now that if you divide 120 by 600 you get the correct answer, but he apparently decided on some other operation which I still can't fath... oh dear God. He added them together.
I'm not a math teacher anymore, praise Babbage, but 120 + 600 isn't 72000. Maybe a multiplier? :D Hey, multiplication is like addition; only with more angst.

I could tell you stories about college level students who couldn't do simple algebra, but it would depress everyone.
 

Starfishied

Diabloii.Net Member
Do you plan to speak to the kid about it? Sometimes when the time is limited, I just hurried and tried to get over with the questions. Talk it out or you'll see more of that math problems.
 

jizus

Diabloii.Net Member
cougar said:
ask him?


yay 10 chars!
best advice i've ever seen. just corner the lil bugger and ask em how on earth those outcomes came up, preferably in a loud, shocked voice, and possibly do the same to the parents afterwords
 

Lithium

Diabloii.Net Member
Seems like he just made a little mistake. At our school we actually get the points not for the answer but for what we attempt to do.
 

toader

Banned
Munch said:
I'm guessing he hit the wrong button on the calculator. 120x600=72000.

Thats the first thing that came to my mind. I dont understand what the big hoopla is all about. The / and * keys are pretty close on a calculator. Seems all you really need to discuss with him is profficiency and checking his work.
 

tarnok

Diabloii.Net Member
Once could be a mistake. Twenty-two times makes it less acceptable. Added to which the fellow who was apparently working with him wasn't able to spot the mistakes.

I was working with the first boy yesterday afternoon after school. It struck me then that he didn't seem to be able to differentiate between different opperations consistently. I hope that he will come by again. Whatever it is he needs some help.
 
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