Comments on: Be careful in solving K-12 math problem: divison by zero http://singularity.agronesia.net/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/ A personal changelog of Agro Rachmatullah Sat, 19 May 2012 03:09:34 +0000 http://wordpress.org/?v=2.5.1 By: jd2718 http://singularity.agronesia.net/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/#comment-158 jd2718 Sat, 06 Jan 2007 14:41:35 +0000 http://agro1986.wordpress.com/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/#comment-158 Perhaps a better title would have been: Be careful in <i>posing k-12 math problems... It is true that teachers and problem writers sometimes forget to properly restrict division by 0. More often than they should. But students should learn to distinguish between an inadvertant omission and a genuine problem, and react accordingly. I actually consider it a measure of how well I've taught that students will quickly remind me if I've absent-mindedly failed to introduce necessary restrictions. Jonathan</i> Perhaps a better title would have been: Be careful in posing k-12 math problems…

It is true that teachers and problem writers sometimes forget to properly restrict division by 0. More often than they should. But students should learn to distinguish between an inadvertant omission and a genuine problem, and react accordingly.

I actually consider it a measure of how well I’ve taught that students will quickly remind me if I’ve absent-mindedly failed to introduce necessary restrictions.

Jonathan

]]> By: Agro Rachmatullah http://singularity.agronesia.net/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/#comment-156 Agro Rachmatullah Tue, 26 Dec 2006 12:18:12 +0000 http://agro1986.wordpress.com/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/#comment-156 And the necessary steps to avoid getting 0/0 = 3 is.... a * b = c (a * b) / b = c / b, with b not 0 (we must put this restriction, because we are doing division with b) a * (b / b) = c / b, with b not 0 (yup the restriction will stay until the end of the world) a = c / b, with b not 0 c / b = a, with b not 0 Now you cannot plug b = 0 to the last equation, because there's this limitation "with b not 0" :) And the necessary steps to avoid getting 0/0 = 3 is….

a * b = c
(a * b) / b = c / b, with b not 0 (we must put this restriction, because we are doing division with b)
a * (b / b) = c / b, with b not 0 (yup the restriction will stay until the end of the world)
a = c / b, with b not 0
c / b = a, with b not 0

Now you cannot plug b = 0 to the last equation, because there’s this limitation “with b not 0″ :)

]]> By: Aziz http://singularity.agronesia.net/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/#comment-157 Aziz Tue, 26 Dec 2006 05:14:51 +0000 http://agro1986.wordpress.com/2006/12/23/be-careful-in-solving-k-12-math-problem-divison-by-zero/#comment-157 a*b=c c/b=a Example= 3*2=6 6/2=3 OR 3*0=0 0/0=3 a*b=c
c/b=a

Example=
3*2=6
6/2=3

OR

3*0=0
0/0=3

]]>