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Some people can't memorize times tables, so the common core algorithm might be more generally applicable for those people even if it's less efficient than using

Some people can't memorize times tables, so the common core algorithm might be more generally applicable for those people even if it's less efficient than using a table. There's some value in finding an approach that works for everyone as an educator instead of one that works for Most if you can do that, I think. In CPU terms, maybe you don't always have the die space for all the tables you need to make a blazing fast implementation of mul or sin or cos, but you can afford to fit a slow iterative solution instead.

cyberax 4y ago
> Some people can't memorize times tables Well, perhaps then schools need to be fixed? Memorization is a skill like anything else, and it can be trained via a variety of ways (memory palaces, mnemonics, writing stuff down by hand). If a student can't remember ~20 non-trivial entries in the multiplication table, then they likely will struggle with anything else non-trivial. > There's some value in finding an approach that works for everyone as an educator instead of one that works for Most if you can do that, I think. Also known as "dumbing down the education". There are trade-offs everywhere. The lattice method simplifies bookkeeping on paper, but try to visualize it for mental math and you'll likely fail. While the classic textbook algorithm is fairly easy to do. So the lattice method is optimized for a use-case that never really matters in practice: being able to multiply numbers on a piece of paper, while not having access to a calculator. While it's pessimized for a use-case that actually matters once in a while: pure mental math.
- alpaca128 4y ago
  Your conclusion that schools should be fixed is correct, but the important part is making it flexible enough to handle different kinds of students. As long as the school system teaches and treats everyone exactly the same there will be people failing because they can't keep up and others because they're so bored out of their mind (and then punished for it) they start hating education and learning.
- iglio 4y ago
  I am one of those people that cannot memorise times tables. That hasn’t stopped me getting a degree in computer science, and working for a FANG since I graduated nearly 10 years ago as a software engineer. I have provided value. I can do just fine in the real world without having memorised the times tables. Different people have their heads wired differently. I was lucky enough to be in a state school that had a great learning support program, and some teachers that saw potential in me despite struggling with some conventionally trivial aspects of education. The solution after diagnosis[1]? Just give me a calculator (I was allowed to use one in the normally “non calculator” exams). And in a pinch, I can still do it by hand but slowly. I often don’t just “know” the result, and that’s something I’m fine with not being “fixed” about me. [1] https://www.bdadyslexia.org.uk/dyscalculia/how-can-i-identify-dyscalculia/how-to-identify-dyscalculia https://www.bdadyslexia.org.uk/dyscalculia/how-can-i-identif...
  - cyberax 4y ago
    > I am one of those people that cannot memorise times tables. Have you actually tried that? Just rote-learning it as a chant or using any other method? Or by copying it down by hand several times? Memorization is a trainable skill, and it's often overlooked in the US. > I can do just fine in the real world without having memorised the times tables. You can live just fine without long multiplication, division, and even basic math, physics or chemistry. You can even get university degrees. It's absolutely true. It's not the question of necessity.
    - abecedarius 4y ago
      The way I learned it was by keeping an actual printed table handy to look at during multiplication problems. For me at least, that didn't take long and never required memorizing "for its own sake" -- I don't know if that'd generalize, since I don't know of anyone else going that way. Learning by chant or whatever just seemed super boring (and prone to learning sequential access rather than as random access). The same principle helped for touch typing and dvorak: tape a layout card to your screen at first.
      - 4y ago
cyberax 4y ago
> There's some value in finding an approach that works for everyone as an educator instead of one that works for Most if you can do that, I think. "Dumbing down" really seems to be an apt description of this. It's interesting that the US school math scores started to go down after the Common Core implementation, after decades of gradual rise: https://nces.ed.gov/fastfacts/display.asp?id=38 https://nces.ed.gov/fastfacts/display.asp?id=38

cyberax 4y ago

> Some people can't memorize times tables Well, perhaps then schools need to be fixed? Memorization is a skill like anything else, and it can be trained via a variety of ways (memory palaces, mnemonics, writing stuff down by hand). If a student can't remember ~20 non-trivial entries in the multiplication table, then they likely will struggle with anything else non-trivial. > There's some value in finding an approach that works for everyone as an educator instead of one that works for Most if you can do that, I think. Also known as "dumbing down the education". There are trade-offs everywhere. The lattice method simplifies bookkeeping on paper, but try to visualize it for mental math and you'll likely fail. While the classic textbook algorithm is fairly easy to do. So the lattice method is optimized for a use-case that never really matters in practice: being able to multiply numbers on a piece of paper, while not having access to a calculator. While it's pessimized for a use-case that actually matters once in a while: pure mental math.

alpaca128 4y ago
Your conclusion that schools should be fixed is correct, but the important part is making it flexible enough to handle different kinds of students. As long as the school system teaches and treats everyone exactly the same there will be people failing because they can't keep up and others because they're so bored out of their mind (and then punished for it) they start hating education and learning.
iglio 4y ago
I am one of those people that cannot memorise times tables. That hasn’t stopped me getting a degree in computer science, and working for a FANG since I graduated nearly 10 years ago as a software engineer. I have provided value. I can do just fine in the real world without having memorised the times tables. Different people have their heads wired differently. I was lucky enough to be in a state school that had a great learning support program, and some teachers that saw potential in me despite struggling with some conventionally trivial aspects of education. The solution after diagnosis[1]? Just give me a calculator (I was allowed to use one in the normally “non calculator” exams). And in a pinch, I can still do it by hand but slowly. I often don’t just “know” the result, and that’s something I’m fine with not being “fixed” about me. [1] https://www.bdadyslexia.org.uk/dyscalculia/how-can-i-identify-dyscalculia/how-to-identify-dyscalculia https://www.bdadyslexia.org.uk/dyscalculia/how-can-i-identif...
- cyberax 4y ago
  > I am one of those people that cannot memorise times tables. Have you actually tried that? Just rote-learning it as a chant or using any other method? Or by copying it down by hand several times? Memorization is a trainable skill, and it's often overlooked in the US. > I can do just fine in the real world without having memorised the times tables. You can live just fine without long multiplication, division, and even basic math, physics or chemistry. You can even get university degrees. It's absolutely true. It's not the question of necessity.
  - abecedarius 4y ago
    The way I learned it was by keeping an actual printed table handy to look at during multiplication problems. For me at least, that didn't take long and never required memorizing "for its own sake" -- I don't know if that'd generalize, since I don't know of anyone else going that way. Learning by chant or whatever just seemed super boring (and prone to learning sequential access rather than as random access). The same principle helped for touch typing and dvorak: tape a layout card to your screen at first.
    - 4y ago

cyberax 4y ago

> There's some value in finding an approach that works for everyone as an educator instead of one that works for Most if you can do that, I think. "Dumbing down" really seems to be an apt description of this. It's interesting that the US school math scores started to go down after the Common Core implementation, after decades of gradual rise: https://nces.ed.gov/fastfacts/display.asp?id=38 https://nces.ed.gov/fastfacts/display.asp?id=38