Classroom snippets, mathematical musings, school activities, and personal grumblings.Tumblr (3.0; @therationalradical)http://therationalradical.tumblr.com/<img src="http://25.media.tumblr.com/4ca9b740f3554b01b197ee3ffe307bd9/tumblr_ml3vt9dNUJ1qbr8m0o1_500.jpg"/><br/><br/><p><a href="http://world-shaker.tumblr.com/post/47796655499/teens-abandoning-social-networks-study-says" class="tumblr_blog">world-shaker</a>:</p> <blockquote><p><strong><a href="http://www.buzzfeed.com/jwherrman/are-teens-abandoning-social-networks">Teens Abandoning Social Networks, Study Says</a></strong></p> <blockquote> <p>Facebook is the “most important” social media site for about 10% fewer teenagers than it was a year ago, according to a new <a href="http://www.piperjaffray.com/private/pdf/Taking_Stock_Teach-in_Spring_2013_MV_2.pdf">PiperJaffray survey</a> of over 5,000 teenagers. The teens surveyed are less interested in Twitter, YouTube, Google+, Flickr, and Tumblr too. Of the major sites included in the survey, only Pinterest has grown. (Instagram was not included in the survey in spring 2012).</p> </blockquote></blockquote>http://therationalradical.tumblr.com/post/47835463110http://therationalradical.tumblr.com/post/47835463110Fri, 12 Apr 2013 23:30:08 -0400<p><a href="http://backwardinduction.tumblr.com/post/47814897848/today-my-abstract-algebra-professor-literally" class="tumblr_blog">backwardinduction</a>:</p> <blockquote><p>Today my abstract algebra professor literally wrote “use magic” in a proof on the board today because he was too lazy to prove one of his claims.</p></blockquote>http://therationalradical.tumblr.com/post/47834507819http://therationalradical.tumblr.com/post/47834507819Fri, 12 Apr 2013 23:17:46 -0400<p>To my tiny army of followers: I am tweeting things about math and education and thangs and stuff. You can read it at <a href="http://www.twitter.com/dave_sabol">twitter.com/dave_sabol</a>. </p>http://therationalradical.tumblr.com/post/47324796572http://therationalradical.tumblr.com/post/47324796572Sat, 06 Apr 2013 21:28:00 -0400<a href="http://www.theverge.com/2013/3/29/4159928/russian-photos-from-top-of-egypt-pyramids-stir-controversy#.UWCEoiS2oJg.tumblr">Russian photographers secretly scale Pyramids to capture gorgeous images | The Verge</a>: <p><a class="tumblr_blog" href="http://revolutionizeed.tumblr.com/post/47302193966/russian-photographers-secretly-scale-pyramids-to">revolutionizeed</a>:</p> <blockquote> <p>Need to share this with my students as we talk about Egypt very soon…</p> </blockquote>http://therationalradical.tumblr.com/post/47324239234http://therationalradical.tumblr.com/post/47324239234Sat, 06 Apr 2013 21:20:58 -0400<img src="http://25.media.tumblr.com/tumblr_m7znnfQIOZ1r6t03po1_500.jpg"/><br/> <br/><img src="http://24.media.tumblr.com/tumblr_m7znnfQIOZ1r6t03po2_500.jpg"/><br/> <br/><blockquote> <div>An interactive installation, “Measuring the Universe” by  Roman Ondak, in which visitors mark their height in black ink on a white wall, representing a star in a network of celestial bodies to symbolize the space each individual takes up in our vast universe.</div> </blockquote> <p></p>http://therationalradical.tumblr.com/post/43360415232http://therationalradical.tumblr.com/post/43360415232Sun, 17 Feb 2013 20:26:01 -0500<a href="http://healthland.time.com/2012/12/26/motivation-not-iq-matters-most-for-learning-new-math-skills/">Motivation > IQ</a>http://therationalradical.tumblr.com/post/39381521083http://therationalradical.tumblr.com/post/39381521083Tue, 01 Jan 2013 09:21:05 -0500matheducation<img src="http://25.media.tumblr.com/cea5004fa3d73d76e2ed7a59c838c289/tumblr_mfxe86vhjj1qfmqapo1_r3_500.jpg"/><br/> <br/><img src="http://24.media.tumblr.com/565cea39db7d89e5f9f1650420a4527c/tumblr_mfxe86vhjj1qfmqapo2_500.jpg"/><br/> <br/><p><a class="tumblr_blog" href="http://appliedmathemagics.tumblr.com/post/39360911520/lets-take-a-moment-to-admire-the">appliedmathemagics</a>:</p> <blockquote> <p>Let’s take a moment to admire the beautiful <strong>icosahedral geodesic sphere</strong> known as the Times Square Ball.</p> </blockquote>http://therationalradical.tumblr.com/post/39381300360http://therationalradical.tumblr.com/post/39381300360Tue, 01 Jan 2013 09:14:29 -0500<img src="http://25.media.tumblr.com/c72e71c1c3fb401dc2ebfb08e9c3635d/tumblr_mf9bbaLH0q1qkdybeo1_500.png"/><br/><br/><p>Hipster Venn Diagram</p>http://therationalradical.tumblr.com/post/38274043540http://therationalradical.tumblr.com/post/38274043540Tue, 18 Dec 2012 21:37:00 -0500math<iframe width="400" height="225" src="http://www.youtube.com/embed/jK7xPo1YXzY?wmode=transparent&autohide=1&egm=0&hd=1&iv_load_policy=3&modestbranding=1&rel=0&showinfo=0&showsearch=0" frameborder="0" allowfullscreen></iframe><br/><br/><p>The Museum of Math has opened! </p>http://therationalradical.tumblr.com/post/37944937684http://therationalradical.tumblr.com/post/37944937684Fri, 14 Dec 2012 19:56:00 -0500mathvideo<p>You could say that. You could also say I teach there. Or that I teach math there. I’m Mr. Sabol.</p>http://therationalradical.tumblr.com/post/37092088002http://therationalradical.tumblr.com/post/37092088002Sun, 02 Dec 2012 23:33:36 -0500<iframe width="400" height="225" src="http://www.youtube.com/embed/pjrI91J6jOw?wmode=transparent&autohide=1&egm=0&hd=1&iv_load_policy=3&modestbranding=1&rel=0&showinfo=0&showsearch=0" frameborder="0" allowfullscreen></iframe><br/><br/>http://therationalradical.tumblr.com/post/36257493965http://therationalradical.tumblr.com/post/36257493965Wed, 21 Nov 2012 22:05:37 -0500videoVi Hart<iframe width="400" height="225" src="http://www.youtube.com/embed/4tsjCND2ZfM?wmode=transparent&autohide=1&egm=0&hd=1&iv_load_policy=3&modestbranding=1&rel=0&showinfo=0&showsearch=0" frameborder="0" allowfullscreen></iframe><br/><br/>http://therationalradical.tumblr.com/post/36257461173http://therationalradical.tumblr.com/post/36257461173Wed, 21 Nov 2012 22:05:08 -0500videoVi Hart<iframe width="400" height="300" src="http://www.youtube.com/embed/XwIs1nlDQ2I?wmode=transparent&autohide=1&egm=0&hd=1&iv_load_policy=3&modestbranding=1&rel=0&showinfo=0&showsearch=0" frameborder="0" allowfullscreen></iframe><br/><br/>http://therationalradical.tumblr.com/post/36257411369http://therationalradical.tumblr.com/post/36257411369Wed, 21 Nov 2012 22:04:21 -0500videoVi Hart<iframe width="400" height="300" src="http://www.youtube.com/embed/F5RyVWI4Onk?wmode=transparent&autohide=1&egm=0&hd=1&iv_load_policy=3&modestbranding=1&rel=0&showinfo=0&showsearch=0" frameborder="0" allowfullscreen></iframe><br/><br/>http://therationalradical.tumblr.com/post/36257366890http://therationalradical.tumblr.com/post/36257366890Wed, 21 Nov 2012 22:03:40 -0500Vi Hartvideo<img src="http://24.media.tumblr.com/tumblr_mcmmzpEkgL1qkdybeo1_500.jpg"/><br/><br/><p><a href="http://www.utopiadesign.cn/en/FibonacciCabinet.html">Please deliver to me yes. </a></p>http://therationalradical.tumblr.com/post/34524908098http://therationalradical.tumblr.com/post/34524908098Sun, 28 Oct 2012 19:37:55 -0400designmath<p>I learned this morning that Rick Parris, a math instructor at Phillips Exeter Academy passed away earlier this week. I can&#8217;t say that I knew him well personally, but I have admired his work for a long time. I had the distinct privilege of working with him at a workshop he taught this past summer. The connections he made were astounding. I have never met someone who was at once so intelligent and so capable of helping another discover his vision via a set of brilliantly crafted questions. Rick communicated through questions. In addition to writing the widely-used <a href="http://math.exeter.edu/rparris/winplot.html">WinPlot</a> software package, he was one of the primary authors of the famous (for me) Phillips Exeter Academy problems sets which make up Exeter&#8217;s 4 year math curriculum. </p> <p>In his memory take some time to deliberate on this question, #2 on the Math 1 problem set: </p> <p><em>How long would it take you to count to one billion, reciting the numbers one after another? First write a guess into your notebook, then come up with a thoughtful answer. One approach is to actually do it and have someone time you, but there are more manageable alternatives. What assumptions did you make in your calculations? </em></p>http://therationalradical.tumblr.com/post/34324059799http://therationalradical.tumblr.com/post/34324059799Thu, 25 Oct 2012 19:14:00 -0400“About that edge-of-space Jump: A coresponding fall to a schoolroom globe begins 1 millimeter above its surface. I’m just saying.”<br/><br/> - <em><span>NDTyson</span></em>http://therationalradical.tumblr.com/post/33603126103http://therationalradical.tumblr.com/post/33603126103Sun, 14 Oct 2012 19:35:38 -0400<img src="http://24.media.tumblr.com/tumblr_ma1gp7z1PJ1qiqoyoo1_500.jpg"/><br/><br/><p><a class="tumblr_blog" href="http://themathkid.tumblr.com/post/33268400316/have-i-mentioned-i-have-a-thing-for-absurdity">themathkid</a>:</p> <blockquote> <p>Have I mentioned I have a thing for absurdity?</p> </blockquote>http://therationalradical.tumblr.com/post/33537283135http://therationalradical.tumblr.com/post/33537283135Sat, 13 Oct 2012 22:09:47 -0400<img src="http://24.media.tumblr.com/tumblr_mbll24vGbK1qkdybeo1_500.jpg"/><br/><br/><p>Public Square in Cleveland, OH, 1900</p>http://therationalradical.tumblr.com/post/33193667255http://therationalradical.tumblr.com/post/33193667255Mon, 08 Oct 2012 19:25:16 -0400cleveland<img src="http://24.media.tumblr.com/tumblr_mbjbxuekNg1rwe5kgo1_500.png"/><br/><br/><p><a class="tumblr_blog" href="http://ulaulaman.tumblr.com/post/33102994787/numbers-are-simple-via-smoot-brokvisk">ulaulaman</a>:</p> <blockquote> <p>Numbers are simple.</p> <p><small>via <a href="http://smoot.tumblr.com/post/33102825574/brokvisk-numbers-are-simple" target="smoot">smoot</a> | <a class="tumblr_blog" href="http://brokvisk.tumblr.com/post/33097530806/numbers-are-simple">brokvisk</a></small></p> </blockquote>http://therationalradical.tumblr.com/post/33192453583http://therationalradical.tumblr.com/post/33192453583Mon, 08 Oct 2012 19:08:52 -0400