Posted on 10/04/2013 9:46:54 AM PDT by Impala64ssa
By this method, 34 + 29 = 40 + 23 (add 6 to 34, subtract it from 29) + 63.
The method doesn't work for say 32 + 14, but you don't need it because there's no regrouping.
This "method" looks to be a pretty good coping strategy from someone who had a horrible math background, but somehow (we know how) became a teacher. JMHO
Agree, add up the columns (displaying the numbers horizontally makes for easy typing by not “cyphering”) from smallest figure (rightmost) and carrying the 1’s (10’s etc.) is still the tried and true method.
I also do darkroom photography and mix chemicals. They are recommended to be at certain temperatures (and the equalize the temperatures between the chemistry so that there isn’t a wide difference than may “shock” the film transparency or emulsion on paper).
Warmer or cooler developer temperatures can also affect the time for development to occur (leading to over/under developed film).
After adhering to the “recommendations” for a period of time, you can stray from the norms with the UNDERSTANDING of what the outcome will be. But it shouldn’t be the starting point.
Measure twice. Cut once. Always good practice.
I don’t think Newton and Einstein needed a piece of paper for that. Really if you understand how to chunk up numbers it’s easy, you’ve got one that’s 6 above 150 and one that’s 1 below 75, which makes it 225 + 5 = 230. That’s the point of this style of math, to be able to do that in your head. The whole thing is a severe abuse of the commutative property of math.
I agree. My brother had a daughter having a difficult time with basic math. He taught her the way he learned, with all the traditional simple tables and a series of simple problems to understand the concepts. She finally got it, but it took parental involvement and a traditional approach. Whatever "Common Core" is, it doesn't teach kids math, IMHO.
Uh ... I have my old textbooks and sometimes carry them without a license?
Uh ... I apply for a grant, and then use the money to build a secure vault in which to hide all the good, old textbooks from the liberal nitwits?
Uh ... Do we need a 22nd Amendment to affirm our Right to Keep and Bear Books, or will the liberals insist that only the the[ir] government should have books, because they’re “trained better, to use them?”
You are on to something! If you can't dazzle them with brilliance, baffle them with bulls**t.
Seems like a convoluted approach though...???
In my defense, if there *is* already a 22nd Amendment, well, I lost interest after reading the 17th.
It’s a great way to do it. Let’s you do a lot more math in your head. It’s all about understanding that there are hard numbers to work with and there are easy numbers to work with but that you can make ALL numbers easy to work with if you understand that not stone concepts but clay concepts that can be manipulated that in fact the whole POINT of math is manipulating the clay. 3rd grade might be a little early for it, but maybe not, once you get skill at dissecting numbers big weird hairy numbers get a lot less intimidating.
Of course, the kids gotta start somewhere; I still don't think that it is a good idea to teach that process early on.
"ballpark numbers" - like approximating at infinity in diffy Q
Glad you posted that. That's how I do it, too.
The numbers don’t even have to be that large to see if they grasp the concept.
3x7=?
a) 1
b) 10
c) 21
d) 98
You got further than me. I threw the towel in on the whole mess at the 16th. :-(
Yep. In training I always taught the "long way" first and then taught the short cuts and when you could use them.
There was some grumbling about how I was "wasting time" by not teaching the short cuts first so I would always have something that if you used the short cuts you would get the wrong results.
That usually stopped the grumbling.
I was thinking 7+6=13, carry 1; 1+2+1=4; 43
Or 26 + 14 = 40, + 3 = 43
Or 26 + 10 = 36, + 7 = 43
I like the first one best.
It’s much easier to “see where the cart went off the tracks” if students show their work using the “long” (or explicit) method.
Using fuzzy logic to feel out numbers (without writing down what you did) is asking for problems (will the student even be able to recall how (s)he arrived at that conclusion?)
If there is no indication “where you went wrong”, the red pen does nothing to point the way to ARRIVING at the right answer.
LOL!
Gov’mint maff sho iz funs
“Seems unnecessarily complicated.”
Ditto
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