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# Posts

### December 22, 2014

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Another problem to kick off the week, once again adapted from Henry Dudeney:Max, who already has some children from a prior marriage, marries the widow Wilma who also has some prior children. A dozen years later their family has a total of 12 children, including all prior children and the new ones resulting from their marriage. Each partner, Max and Wilma, have 9 children (out of the 12) that they are direct parents of.  How many children have been born to Max and Wilma together in the […]
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Here’s a new numberiffic game from Veewo, the people who made noted Threes-a-like 1024 (which begat 2048, which inevitably begat 2048: Harry Styles edition). In Just Get 10, you have to get at least nineteen combine numbered blocks until you get one with a 10 on it. If you tap two adjacent blocks with the same number, they’re... Read more »
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justasipwetyourlips: watcheditbegin: Dear person reading this, You made it through another year. You made it through the hard times and pain. You made it through all the times when you all you wanted to do was give up. You made it. You made it another year and I promise you can make it another year. I am SO proud of you. I needed this.
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The song “The Twelve Days of Christmas” is a carol where the number of gifts keeps increasing cumulatively each day. On the Nth day, the recipient gets N gifts, plus the number of gifts given on each previous days. How many gifts are given in all for the 12 days? What’s a general formula? Here […]
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This is the eighth year that I'm doing Christmas comics, and in that times I've amassed nearly two dozens posts with the Christmas tag. (And there are random posts missing the tag that should have it.) This begs the question: Which is your favorite (x, why?) Christmas comic?An older one? A newer one? A song or carol? A puzzle? I probably should have made an online survey ... but past experience tells me that I'll get fewer than 10 responses (likely much fewer).
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audi-vide-disce: Incredible (

### December 21, 2014

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12 / 2 = 1 + 1 + 4 Also: 12 * 2 * 1 * 1 = 4! Also: 12 / (2 + 1) = 1 * 4 Also: 1 + 2 + 2 = (1 * 1) + 4 Also: (1 * 2) + (2 * 1) = 1 * 4
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The unexplained mystery..."I, for one, find Gödel's incompleteness theorems rather comforting. It means that mathematicians will never be complete. There will always be something else which is undecidable with the current axioms. Should the human species survive another few million years and continue churning out mathematics at the rate we've done for the past few thousand years, we still won't have considered it all. There will always be work for all of the future mathematicians. As always, […]
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Source: Sent to me by Pritish Kamath (http://www.mit.edu/~pritish/) Problem: Have you ever played "SET"? You have to play it. http://www.setgame.com/learn_play http://www.setgame.com/sites/default/files/Tutorials/tutorial/SetTutorial.swf Even if you have not played the game, the game can be stated in a more abstract way as follows: There are 12 points presented in F34 and the first person to observe a "line" amongst the 12 given points gets a score. Then the 3 points forming […]
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I have given you a lot of gift ideas for Christmas (Christmas Presents, for her, for him, for children), but I thought that it would be a good idea to do a DIY. Also, this is not a really maths … Continue reading →
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curiosamathematica: Last week my follower count hit 10.000. Which is simply amazing. When I started this blog one and a half years ago, I would never have believed it would grow to be this popular. So, let me start with a big THANK YOU to all my amazing followers! To celebrate this milestone, I would like to organize some mathematical giveaway. First, what can you win? Well, a signed edition of this delightful new book of Matt Parker, Things to Make and Do in the Fourth Dimension! I bought the […]

### December 20, 2014

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"Εάν μπόρεσα να δω πιο μακριά, είναι γιατί στεκόμουν πάνω σε ώμους γιγάντων."                    […]
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(Click on the comic if you can't see the full image.) (C)Copyright 2014, C. Burke.Expressing my True Love mathematically and recursively. This comic calls to mind my Twelve Triangle Numbers of Christmas from way back in 2007. Once again, I used pseudo-code here, and not any particular programming language. I wouldn't program it exactly like this, but I wanted it to be readable. As for the summations, those actually caused me some problems -- or at least a bit of thought about how they […]
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Introduction In earlier parts we discussed about the basics of integral equations and how they can be derived from ordinary differential equations. In second part, we also solved a linear integral equation using trial method. Now we are in a situation from […] Visit the original post Solving Integral Equations (4) : Integral Equations into Differential Equations for the best experience of reading!
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12 * (2 + 0) = 1 * 4! Also: 1 + 2 + 2 + 0 = 1 + 4 Also: 1 + 2 - 2 + 0 = 1^4 Also: 1 * 2 * 2 = (0 + 1) * 4
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An incomplete Android App is in development at GATILAB. You can download it directly from dropbox and help us debug it by sending feedback and bug reports. Screenshots Visit the original post Android App for the best experience of reading!
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Spotted on the Web: The Political Hat had a post about the Common Core in Jeopardy category. What makes this interesting is that there was an "Update" to the common with a link to my column from two weeks ago. (Yeah, me!) Maybe this is the reason that Michelle Malkin of Twitchy.com suddenly started following me out of the blue. (Double Yeah, me!) The fame is going full-circle. Or inside-out. Or something. Moving up from the H-list to the G-list. I'll be on the D-list before you know it! The […]
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No summary available for this post.
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Welcome to the 81st edition of Math Teachers at Play (MTaP) Blog Carnival. I am extremely exited to host this post in my favorite month of the year, December. In case you don’t know much about this carnival I encourage … Continue reading →

### December 19, 2014

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This week's grab-bag (and I will either have NO weekly potpourri next week, or else it will appear on Sunday, rather than on Friday, the day after Christmas): 1)  Recent New Zealand interview with Marcus du Sautoy here: http://www.radionz.co.nz/national/programmes/saturday/audio/20160965/marcus-du-sautoy-maths-and-art ...related Sautoy article here: http://www.odt.co.nz/lifestyle/magazine/
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Ask a spectator to pick any 3-digit number. On a calculator, they multiply the number by 7, then by 11, and then by 13. Before they can read the result you already call out the answer. How is this possible? It’s a trick anyone can pull off. (To vary the trick, you can ask them […]
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12 - 1 - 9 = 1 * √4 Also: 1 * 2 * 1 = (9 - 1) / 4 Also: 1 + 2 + 1 = 9 - 1 - 4
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Every so often we come across an integral that seems absolutely impossible on its face, but is easily attacked – in fact, is custom designed – for the residue theorem. I wonder why a first year complex analysis class doesn’t show off this case as Exhibit A in why the residue theorem is so bleeding’ […]
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A very basic question was asked recently: What is a better approximation to $e^x$, the usual Taylor approximation, or a similar approximation involving $1/e^{-x}$? More precisely, given an integer $m$, which is a better approximation to $e^x$: $$f_1(x) = \sum_{k=0}^m \frac{x^k}{k!}$$ or $$f_2(x) = \frac1{\displaystyle \sum_{k=0}^m \frac{(-1)^k x^k}{k!}}$$ The answer is amazingly simple: […]
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The Story So Far: Personified math made it home, only to be told that their existence was inconsequential. Yet even so, some traditions linger...A whirlpool formed in the middle of the air. It grew rapidly in size, until it was large enough to discharge a blonde bunny onto the ground. Once this had been done, the portal shrank back down and vanished. Para, the personified parabola, tentatively poked at the ground where she had landed - she was unhurt, quite accustomed to doing calculations for […]
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All the incentive you need to solve the Riemann hypothesis.
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Just a couple weeks after Jeopardy had its Non-Common Core Math category during Kids Week, they ventured again into that academic field, but this time with adults. They fared a little better. For one thing, they made it through all five clues, including a Daily Double, and they didn't wait until everything else was exhausted. Unlike the kids' clues, these didn't all have to do with the numbers 1, 2, 3, 4, 5 being added and multiplied. The first question involved calculating a 20% tip on a […]
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Dr. Keith Devlin is a mathematics professor at Stanford University in […]

### December 18, 2014

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We are very close to Christmas and I thought that it would be nice to share with you some of the photos I have made around the city. As you already know (About me) I am living in Aberdeen, Scotland … Continue reading →
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Welcome to this week’s Math Munch! Math projects are exciting—especially when a whole bunch of people work together. One example of big-time collaboration is the GIMPS project, where anyone can use their computer to help find the next large prime number. Another is the recent MegaMenger project, where people from all over the world helped to build […]