4 ms·

I haven't seen any real arguments to the substance. I keep seeing that one picture reposted with the "Old Fashioned" method and the "Common Core" method[1], and

I haven't seen any real arguments to the substance. I keep seeing that one picture reposted with the "Old Fashioned" method and the "Common Core" method[1], and although I don't know anything about Common Core, I can see that it is a clearly contrived example that is certainly very misleading. Every other criticism is consistent with your experience, essentially calling it overreaching or teachers complaining that they shouldn't have to learn it to teach their kids. [1] http://www.thefederalistpapers.org/wp-content/uploads/2014/06/14142835727258.jpg http://www.thefederalistpapers.org/wp-content/uploads/2014/0... (this was the first Google hit for the image I was looking for)

bsder 11y ago
Um, I think that diagram is wrong. The common core example I have seen would break the subtraction into "32 - 12" = "32 - 10 = 22 22 - 2 = 20" Which is how almost every engineer I know would do the math in their head. If they didn't just go "30 - 10 or roughly 20" (obviously most engineers can do that simple a subtraction completely--but the number of times I estimate something by lopping off everything except the leading digit is quite high). Note that this is teaching "estimation" almost by osmosis. The "standard" procedure of starting from the least significant digit and "borrowing" obscures estimation.
- ctdonath 11y ago
  The catch is: we engineers do that because we grok basic math so well that we can mentally juggle numbers fast. Yes, seems Common Core is trying to teach those methods - but to children who barely grasp the subject, and thus must memorize rote processes to scribble down all the obligatory steps without understanding why they're doing it. Children need learn math by concrete manipulatives, handling the physical-world form until they (individually!) internalize the process, then growing comfortable enough with those internalized processes to develop more sophisticated AND casual ways to mentally tear numbers apart & rearrange them to perform calculations fast.
  - bsder 11y ago
    > Yes, seems Common Core is trying to teach those methods - but to children who barely grasp the subject, and thus must memorize rote processes to scribble down all the obligatory steps without understanding why they're doing it. The rote processes Common Core teaches are closer to what you and I use. Why teach subtraction from least-significant to most significant manipulation and then make students throw that away and relearn the other direction? That is especially meaningless when tabular clerical calculation skills have no existence in the modern world. We don't teach children to read from right to left and then force them to relearn reading left to right to read fast. > Children need learn math by concrete manipulatives, handling the physical-world form until they (individually!) internalize the process, then growing comfortable enough with those internalized processes to develop more sophisticated AND casual ways to mentally tear numbers apart & rearrange them to perform calculations fast. And, yet, most significant to least significant is almost always how we manipulate things in the real world. I cut material down to rough size, and then I cut it to detailed length. Imperial recipes measure multiple cups and then fractional cups. A bolt looks like a 1/2 inch head, so I try the sockets around my estimate. etc.
    - ctdonath 11y ago
      Most from-fundamentals education involves learning small steps which are later discarded in favor of radically different processes not easily understood without having gone thru those prior steps. Better reading analogy [I read very fast]: we don't teach children to glance at a page, absorb random words, predict likely filler content, identify interesting sections, and repeat process on those sections - instead, we teach children to read left-to-right, word-for-word, until they can do so well enough & fast enough that they internally develop content prediction techniques leading to "page at a glance" reading.
cbd1984 11y ago
> the "Common Core" method No such thing. Common Core doesn't specify methods, it specifies that students must attain specific things by specific times. Methods are left up to individual districts, as they have always been.

bsder 11y ago

Um, I think that diagram is wrong. The common core example I have seen would break the subtraction into "32 - 12" = "32 - 10 = 22 22 - 2 = 20" Which is how almost every engineer I know would do the math in their head. If they didn't just go "30 - 10 or roughly 20" (obviously most engineers can do that simple a subtraction completely--but the number of times I estimate something by lopping off everything except the leading digit is quite high). Note that this is teaching "estimation" almost by osmosis. The "standard" procedure of starting from the least significant digit and "borrowing" obscures estimation.

ctdonath 11y ago
The catch is: we engineers do that because we grok basic math so well that we can mentally juggle numbers fast. Yes, seems Common Core is trying to teach those methods - but to children who barely grasp the subject, and thus must memorize rote processes to scribble down all the obligatory steps without understanding why they're doing it. Children need learn math by concrete manipulatives, handling the physical-world form until they (individually!) internalize the process, then growing comfortable enough with those internalized processes to develop more sophisticated AND casual ways to mentally tear numbers apart & rearrange them to perform calculations fast.
- bsder 11y ago
  > Yes, seems Common Core is trying to teach those methods - but to children who barely grasp the subject, and thus must memorize rote processes to scribble down all the obligatory steps without understanding why they're doing it. The rote processes Common Core teaches are closer to what you and I use. Why teach subtraction from least-significant to most significant manipulation and then make students throw that away and relearn the other direction? That is especially meaningless when tabular clerical calculation skills have no existence in the modern world. We don't teach children to read from right to left and then force them to relearn reading left to right to read fast. > Children need learn math by concrete manipulatives, handling the physical-world form until they (individually!) internalize the process, then growing comfortable enough with those internalized processes to develop more sophisticated AND casual ways to mentally tear numbers apart & rearrange them to perform calculations fast. And, yet, most significant to least significant is almost always how we manipulate things in the real world. I cut material down to rough size, and then I cut it to detailed length. Imperial recipes measure multiple cups and then fractional cups. A bolt looks like a 1/2 inch head, so I try the sockets around my estimate. etc.
  - ctdonath 11y ago
    Most from-fundamentals education involves learning small steps which are later discarded in favor of radically different processes not easily understood without having gone thru those prior steps. Better reading analogy [I read very fast]: we don't teach children to glance at a page, absorb random words, predict likely filler content, identify interesting sections, and repeat process on those sections - instead, we teach children to read left-to-right, word-for-word, until they can do so well enough & fast enough that they internally develop content prediction techniques leading to "page at a glance" reading.

cbd1984 11y ago

> the "Common Core" method No such thing. Common Core doesn't specify methods, it specifies that students must attain specific things by specific times. Methods are left up to individual districts, as they have always been.