This picture says it all
Posted on 03/01/2014 6:02:12 PM PST by dontreadthis
it will drive the bright and creative child into despair
my impression is that, rather than working with individual digits, the emphasis is towards incorporating larger groups of digits.
maybe it’s my imagination, but I can’t see a rational purpose for these contortions
Nevermind my last message. I just called my Son out here to look at this thread’s main picture.
He was all like, “WTF?!?! I do it the old way, Dad.”
WHEW!!!
I never had much interest in math, except geometry, but what strikes me about this calculation is that it seems to be a way of arriving at the answer to a subtraction problem solely by addition (not an efficient way to solve the problem, of course, but a way). It’s like Rush Limbaugh discussing issues with one hand tied behind his back, a conscious restriction (though facetious in his case).
Why they picked those particular numbers to add I don’t know. They seem to be especially easy additions, though. This is the way I’d describe the rule being followed (a good one for persons who can’t subtract :-). Start with the number being subtracted, and in the column beneath it add a number you know you can add successfully (this number must be less than the total being subtracting from). Keep doing this until your total reaches the size of the number being subtracted from. Then add up the numbers you added, and you’ll have the answer — without having done any subtraction.
[That explanation just popped into my head, and I may be wrong about the method or purpose.]
Weird I don’t get it. I would like to see how they check their work.
This picture says it all
I would think you’d have to be bright and creative to keep up with it. It seems like it lacks definite procedures and asks students to cast around for techniques.
Do you mean that it is too slow? Belaboring the obvious?
abacus is resistant to EMP
Wow ... subtraction through reverse construction. I absolutely pity the child making change for a twenty in the checkout line using this method
= = = = = = = = = = = = = =
Exactly. The reason why you can hand a cashier a 25 dollar bill and get the correct change.
Next thing you know the Cash Register Mfgrs will have to put the ONLY possible bills in the amount tendered registry so as the ‘odd ball’ ones get kicked and possibly alert the ‘idiot’ that there may be a problem with the bill presented.
Of course, they will ‘forget’ to add the $2.00 bill and the ‘law suits’ will fly...
Only in the Bizarro World...
I saw a video on this a few months ago, this really is how they’re teaching them these days. The idea is, they figure kids will start to pick better guesses for the arithmetic operators through practice and experience. The experience will magically teach a kid that 30 - 12 = 20. You think this subtraction example is bad? Wait’ll you see long division. I am not kidding you.
Yea,
Numbers 10 or less. A variation of counting on your fingers.
... sounds about right for this. The irony is that it’s very easy to see that you can “count on” by 10’s twice to get from 12 to 32. So I do wonder about the provenance of the example.
I suppose the teachers are liable to become as confused as the students by all this!
I don’t have enough pencil lead for that.
Another example:
20 - 8 = ?
10 + 2 (the numbers added) = 12 (the answer)
If you’re the one who’s Facebook post I saw that related to this, PING!
Okay. My brain’s bleeding...
> A variation of counting on your fingers.
I didn’t think of that. Yes, you could use your fingers for the intermediate additions.
I cant know for certain but I sense that thats exactly the expression Id have on my face if I was forced to go ther commie core route!
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