David Acevedo's Blog

I recently bought myself a Math book that I'm delighted with (Mathematics 1001 by Elwes). I'm finally understanding many math concepts I had not understood in my education and I've reached an few interesting theories on how math should be taught. There should be three things that a math class should teach at the same time: 1. Memorization 2. Visual (Graph-Based) 3. Procedural (Equation-Based) 4. Historical All four are part of a whole and some students will respond better on one than the other. These are four avenues to teach the same thing by the way not three different things. Memorization should begin really early. There is no need to explain how multiplication works to have the kids start to memorize the multiplication table. The reason is not that you * need * to memorize it but  that by doing so or encouraging kids to do so, they'll be faster at doing calculations. Here are the things I think should be memorized in math: a. all the pairs of numbers that...

In this Rails project I'm running I need to set a whole bunch of individual variables to 'disabled' at once depending on the group the current user belongs to. We can use multiple assignment in this case but with a caveat. Multiple assignments are a quick way of setting a lot of variables at once. h, k = 1,2  => [1,2] h => 1 k => 2 but   h, k = 1      => 1 h => 1 k => nil In that case we can do this: h = k = 1   => 1 h => 1 h => 1  Beware this sets them to the same object. So if you change one you change both. h = k = [] h << 1 h => [1] k => [1] While we're at it here is how to reverse two variables: h = 1 k = 2 h,k = k,h h => 2 k => 1

Best explanation of Net Neutrality: Vi Hart . I didn't find a petition in WhiteHouse.gov so I made one: https://petitions.whitehouse.gov/petition/protect-net-neutrality-change-telecommunications-classification-common-carriers/GN70pvdF

Venga a compartir de un regalo fotografico.  La Fundacion Arana abre el espacio para una celebración de cumpleaños y arte fotográfico. “Como el amor, el arte no tiene razón y se entrega enteramente. Celebrando mi cumpleaños voy a dar todas las piezas de la exhibición en un regalo fotográfico.” —David Acevedo Habra vino o sangria, pasen un buen tiempo compartiendo y viendo. El espacio Arana esta localizado en la Calle San Jose 104, Viejo San Juan a un bloque de la alcaldía.  Sábado mayo 17, 2014  7pm Como Llegar? Es Espacio Arana esta bien cerca de la alcaldía de San Juan. En la plaza de Armas mirando hacia el Dept. de Estado vire a la derecha y suba la calle. Tendrá el Meson a mano derecha. Pasara la catedral a la derecha subiendo hacia la san Sebastian y justo después en el medio del bloque a la derecha esta el Espacio Arana.

I've been seeing a lot of bad press for the google buses that ferry people out of San Francisco into the Mountain View Google campus. While I think using the public bus stops might be a problem for other reasons. I think the buses are good overall. Check this comment from Slashdot : "The Director of Sustainability for New York's MTA is calling out Google, Apple, and Yahoo for 'deliberately' building their campuses away from public amenities like restaurants, and public transportation. 'With very few honorable exceptions like Tony Hsieh, the CEO of Zappos, who recently moved his company headquarters from suburban Henderson to downtown Las Vegas, tech companies seem not to have gotten the memo that suburbs are old and bad news,' he writes. Instead of launching their own bus services to ferry people from the city to their campuses, as the tech companies have done, the Googles and Apples of the world should 'locate themselves in existing urban communitie...