Comments on: Math world, simple mental calculations or what’s going on with education? http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/ Take care of the sense, and the sounds will take care of themselves. Tue, 16 Mar 2010 11:21:11 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Getafix http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/comment-page-1/#comment-2918 Getafix Tue, 14 Apr 2009 17:57:28 +0000 http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/#comment-2918 In technologically advanced countries we can't even do simple additions and subtractions without calculators (check out clerks in shops) whereas in technology deprived countries the shopkeepers keep track of your purchases mentally and do it faster than that we do with calculators. Another easy way to accomplish finding squares will be to apply the two formulas (a+b)^2 = a^2 + b^2 + 2*a*b and (a-b)^2 = a^2 - 2*a*b + b^2 as appropriate. These formulas can be used effectively to do mental math. In technologically advanced countries we can’t even do simple additions and subtractions without calculators (check out clerks in shops) whereas in technology deprived countries the shopkeepers keep track of your purchases mentally and do it faster than that we do with calculators.

Another easy way to accomplish finding squares will be to apply the two formulas (a+b)^2 = a^2 + b^2 + 2*a*b and (a-b)^2 = a^2 – 2*a*b + b^2 as appropriate.

These formulas can be used effectively to do mental math.

]]> By: Dano http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/comment-page-1/#comment-2863 Dano Thu, 26 Mar 2009 22:33:46 +0000 http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/#comment-2863 Ok, I must be much younger than you and am terrible at math. I tried to comprehend your first example with 45. Still not making sense, I sure hope the impending nuclear fallout doesn't wipe out calculators. I agree with Christopher and Sergio. If I would have learned some basics, perhaps I could do some harder calculations mentally. Ok, I must be much younger than you and am terrible at math. I tried to comprehend your first example with 45. Still not making sense, I sure hope the impending nuclear fallout doesn’t wipe out calculators.

I agree with Christopher and Sergio. If I would have learned some basics, perhaps I could do some harder calculations mentally.

]]> By: Sergio http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/comment-page-1/#comment-2849 Sergio Sat, 21 Mar 2009 23:38:24 +0000 http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/#comment-2849 everithnig is much easier on thіs painting: In many exUSSR countries scholars learn squares of first 10 2-digit numbers by rote... 10 - 100 11 - 121 13 - 169 14 - 196 15 - 225 16 - 256 17 - 289 18 - 324 19 - 361 20 - 400 everithnig is much easier on thіs painting: In many exUSSR countries scholars learn squares of first 10 2-digit numbers by rote…
10 – 100
11 – 121
13 – 169
14 – 196
15 – 225
16 – 256
17 – 289
18 – 324
19 – 361
20 – 400

]]> By: Christopher Bennage http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/comment-page-1/#comment-2823 Christopher Bennage Fri, 06 Mar 2009 22:38:02 +0000 http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/#comment-2823 I thought that this was only a problem with education in the US. :-( I have a theory (and the evidence continues to support it) that children are born smart and that we adults dumb them down (mostly for our convenience). I thought that this was only a problem with education in the US. :-(
I have a theory (and the evidence continues to support it) that children are born smart and that we adults dumb them down (mostly for our convenience).

]]> By: Ali http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/comment-page-1/#comment-2729 Ali Sun, 08 Feb 2009 17:38:03 +0000 http://khason.net/blog/math-world-simple-mental-calculations-or-whats-going-on-with-education/#comment-2729 Owesome. Shame on bad usage of calculators instead of using our great inner calculator. Owesome. Shame on bad usage of calculators instead of using our great inner calculator.

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