Comments on: NCTM 2010 — Day Three /2010/nctm-2010-%e2%80%94-day-three/ less helpful Mon, 29 Nov 2010 13:50:54 +0000 hourly 1 https://wordpress.org/?v=6.8.2 By: dy/dan » Blog Archive » An Open Video Message To Steve Leinwand And Jerry Becker /2010/nctm-2010-%e2%80%94-day-three/#comment-270960 Mon, 29 Nov 2010 13:50:54 +0000 /?p=6755#comment-270960 […] the third day at NCTM I wrote: It struck me several times throughout both conferences that we need to counter-program a […]

]]> By: Eileen /2010/nctm-2010-%e2%80%94-day-three/#comment-260438 Mon, 17 May 2010 18:06:42 +0000 /?p=6755#comment-260438 I love these! I have a bunch of this type of stuff I have collected over the years, some of it ancient, for ways to include practice without sacrificing higher-level thinking. The kids love it too and they start to see math as the fun game that it is. I think half my job as a middle school teacher is to help kids have good feelings about math so that they actually desire to continue on with it. And that doesn’t mean I have to sacrifice rigor or learning to do so.

]]> By: Dan Meyer /2010/nctm-2010-%e2%80%94-day-three/#comment-260333 Sat, 15 May 2010 03:32:25 +0000 /?p=6755#comment-260333 Got that fixed now. Thanks for the edit.

]]> By: David /2010/nctm-2010-%e2%80%94-day-three/#comment-260315 Fri, 14 May 2010 19:59:11 +0000 /?p=6755#comment-260315 vlk: It’s a typo. The number in the middle rectangle is the sum of the numbers in the adjacent circles, not the difference.

]]> By: vlk /2010/nctm-2010-%e2%80%94-day-three/#comment-260301 Fri, 14 May 2010 14:38:46 +0000 /?p=6755#comment-260301 Sorry, I don’t get the illustrated arithmogon. If I understand the rules correctly, there is no solution to it. If the vertices are A,B, and C, it results in 3 equations,
A-B=7
B-C=9
C-A=8

So C=A+8,
hence B-C=B-A-8=9 ==> B-A=17, but B-A is already stated to be -7.

]]> By: David Radcliffe /2010/nctm-2010-%e2%80%94-day-three/#comment-259969 Wed, 05 May 2010 20:32:22 +0000 /?p=6755#comment-259969 Thanks, this is great stuff! I have saved Becker’s handout for future reference. By the way, the arithmogon problem has an interesting geometric interpretation via inscribed circles. I created a GeoGebra worksheet to demonstrate this at http://cmath.org/incircle.html.

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