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Some things just don't add up

Posted: Mon Dec 21, 2015 2:40 am
by MajGenl.Meade
Image

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 3:00 am
by Econoline
Yeah, at that age I probably would've been just like the kid who answered that question, and for (probably) the same reason: when you find it easy to do calculations like that, quickly, in your head, it's hard to see *WHY* you should ever use a less precise estimate when you don't really need to. Even if/when you understand the concept of estimation, you still don't use it unless you actually need to (in order to save time or effort).

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 3:08 am
by datsunaholic
That's the difference between straight math and estimating. I have to assume that the test in question also had instructions (not visible in the small snippet) which informed the test-taker that they were to estimate at the nearest 10. Otherwise, it IS proper estimating if you assume to round to the nearest whole number...

That being said, I never liked estimating when exact figures are given. Just like I never round when doing my taxes. (wait- I do round and full calculations, and whichever method comes out in my favor is what I use, but that takes twice the effort and the taxed amount usually is exactly the same anyway)

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 10:53 am
by wesw
if they want you to get estimating procedure then they shouldn t use examples that a bright first grader can calculate exactly in their head..., duh

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 12:18 pm
by Guinevere
Actually reading the instructions is an important life lesson.

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 12:24 pm
by MajGenl.Meade
If the question aimed at "estimating", then why did it not suggest 70 or 71 or 72 as a "reasonable answer"? To use the actual (not at all an estimate) accurate number is just seeking trouble - and it's too far from the "estimate" of 70 to be considered "reasonable"

It's not at all reasonable to say that 70 is "close enough" to 75... not when you're my bank teller, or the person steering the plane I'm flying in

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 12:27 pm
by Guinevere
So you and wes agree?

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 12:37 pm
by MajGenl.Meade
Way to spoil a Monday (if that were possible). TKU Guin (not)

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 4:30 pm
by oldr_n_wsr
One must first define "reasonable answer".
75 is a "reasonable answer" to me.
70 is a "guesstimate".

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 5:04 pm
by Fafhrd
75 rounds to 80, so 80 would be a reasonable estimate. 75 is the exact answer. 70 would be too low to be reasonable.

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 6:27 pm
by rubato
Fafhrd wrote:75 rounds to 80, so 80 would be a reasonable estimate. 75 is the exact answer. 70 would be too low to be reasonable.

By law in Calif. blood alcohol results are the average of two measurements and then truncated, not rounded. So two measurements of 0.077 and 0.080 = 0.07 reported value. And it may not be reasonable but its the law.


I couldn't mark that question wrong because you don't illustrate estimation by giving the exact results. Estimation is only of value when exact calculation is more difficult so the child chose the best method from those available.
"... But in the new approach, as you know, the important thing is to understand what you're doing, rather than to get the right answer. Here's how they do it now... " :
T Lehrer


yrs,
rubato

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 10:17 pm
by dales
Guinevere wrote:Actually reading the instructions is an important life lesson.
Not for men, so much. :lol:

Re: Some things just don't add up

Posted: Mon Dec 21, 2015 10:32 pm
by Big RR
Guinevere wrote:Actually reading the instructions is an important life lesson.
I agree, but then I don't see any instructions here, just a question. I don't doubt that there were instructions presented, but I have no idea what they said, how clear they were, etc.

Re: Some things just don't add up

Posted: Tue Dec 22, 2015 5:54 pm
by Fafhrd
I assume that the student had been taught about how to extimate numbers. I agree that giving the exact answer and asking if it was a reasonable estimate was throwing the kid a curve.

Re: Some things just don't add up

Posted: Tue Dec 22, 2015 6:09 pm
by Guinevere
dales wrote:
Guinevere wrote:Actually reading the instructions is an important life lesson.
Not for men, so much. :lol:
That *is* the life lesson . . . :nana

Re: Some things just don't add up

Posted: Tue Dec 22, 2015 7:46 pm
by oldr_n_wsr
I never met a set of instructions I could not write better.