I'm pretty math-challenged these days without a calculator (gone are the days I could run the numbers in my head faster than you could punch them into your calculator), but I tend to do weird things like break stuff down into primes and then multiply it out from there.
The Way You Learned Math Is So Old School
11–20 of 28 posts
Re: The Way You Learned Math Is So Old School
#12I wish to hell I had learned the Soroban growing up. Now it's on my unending todo list. I'll probably make a go at it when my kid is ready for it. We can learn together :)
Re: The Way You Learned Math Is So Old School
#13...Does anyone actually teach their kids with that retarded method? All it does it take up more space, and shift the burden from screwing up carries while multiplying to screwing up carries while adding. And since it's so brain dead to implement, I can't see any significant amount of kids even reflecting on how 'the numbers work' based on that.
As far as I know every child in England is currently being taught this method.
I'm not sure that I would leap to calling it retarded. I agree that it takes up more paper but paper isn't the most expensive thing in the world.
What it does do is make explicit why the old school method works. Look at the explanation given by the article for the old method:
'Answer = 720, Because: 2x36 = 72, with a 0 added in the ones place.'
No, the reason you get 720 isn't because you 'added' a 0 in the ones place (72+0 = 72). It's because you are multiplying by 20 and not by 2. The old method hides this fact and corrects for it by a mechanical process: first write down a zero and then shift the other entries to the left.
Your criticism is analogous to calling Assembly retarded because Haskell exists. They serve different purposes.
Re: The Way You Learned Math Is So Old School
#14I hope that I am not straying off topic, but certainly where I was schooled (Ireland), the main issue in the poor math performance falls on the "uncool" reputation which Maths has received in the past few years.
If you make it so that a child likes maths and feel's no peer pressure to just give up, the way in which one multiplies may become less significant.
Re: The Way You Learned Math Is So Old School
#15This is the way I do multiplications mentally since being a child, but I never quite thought about that fact, that this is "new". How do you guys execute multiplications in mental math?
Re: The Way You Learned Math Is So Old School
#16Aside from the 'new' way of multiplication (which doesn't strike me as too bad), I think asking kids to make a stem-and-leaf plot of the birthdays in their class is actually really cool. It shows them how the things they learn can be applied to real things and it could open the way for interesting discussions as well (though the birthday paradox might be a bit much for 5th graders perhaps).
Re: The Way You Learned Math Is So Old School
#17I have an 11 year old daughter who I help with math homework every week. Some of the new methods work for her, and some are terribly confusing to her. I think it's good to expose kids to a variety of methods in math. I am concerned, however, and the near-complete lack of emphasis on memorizing the basic math tables and doing calculations in your head. Doing that at a young age really helped me to understand numbers. Many of the techniques they teach in school are techniques I figured out on my own by exposing myself to large numbers of calculations.
Re: The Way You Learned Math Is So Old School
#18Either way is fine, I think, if you the child understands the underlying mechanism. I'm the father of a 3rd and 5th grader in US public schools and I think the math curriculum is very good. However, sitting down and explaining basic arithmetic is important. I also teach them to estimate and come up with a quick upper and lower bound before they start the problem.
I went to school in Germany and our methods of multiplication and especially that of long division were a little different. When I first looked at the way long division is done in the US I thought it was confusing and my first reaction was that my method was better. It took a little time to overcome my cultural bias but I'm all better now.
Still waiting for the US to switch to Celsius and metric, though...
Re: The Way You Learned Math Is So Old School
#19Surely that method of multiplication is not suited for larger numbers, to get 246 * 369 u do 200 * 300 200 * 60 200 * 9 40 * 300 40 * 60 40 * 9 6 * 300 6 * 60 6 * 9 So for x-digit multiplied by y-digit u need to write down x*y products and then sum it up, where as for the old method you need to only write down min(x,y) products and sum it up.
This is somewhat misleading. Yes, it's true if
3 * 123456789
But if you're doing the 'old' version you implement it as 9 single digit multiplications:
3*9, 3*8,....,3*1
If you do it with the new method you again get 9 'single' digit multiplications:
3*9, 3*80, ..., 3*100000000
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The old methods efficiency comes from writing the steps out in a compact notation, not from reducing the number of multiplications or additions.
Re: The Way You Learned Math Is So Old School
#20Either way is fine, I think, if you the child understands the underlying mechanism. I'm the father of a 3rd and 5th grader in US public schools and I think the math curriculum is very good. However, sitting down and explaining basic arithmetic is important. I also teach them to estimate and come up with a quick upper and lower bound before they start the problem. I went to school in Germany and our methods of multipl…
I agree. For learning, the method shown is fine. Why? Because it teaches and honors place value, an extremely important concept in developing numeracy. I'm fine with any method that uses that.
I am not fine with something my kids call the "lattice method." The point of this method is simply to get the correct answer for multiplying large numbers. Is it clever? Yes. Does it work? Yes. But it does not teach math. If the educators' goal is simply to give a technique that works and gives the correct answer, teach them to use the calculator on their cell phones.
Lattice method for multiplication:
http://www.coolmath4kids.com/times-tables/times-tables-lesso...