# A math teacher explains so-called "new math"

You've probably seen this image making the rounds on social media. It shows a method of doing basic subtraction that's intended to appear wildly nonsensical and much harder to follow than the "Old Fashion" [sic] way of just putting the 12 under the 32 and coming up with an answer. This method of teaching is often attributed to Common Core, a set of educational standards recently rolled out in the US.

But, explains math teacher and skeptic blogger Hemant Mehta, this image actually makes a lot more sense than it may seem to on first glance. In fact, for one thing, this method of teaching math isn't really new (our producer Jason Weisberger remembers learning it in high school). It's also not much different from the math you learned back when you were learning how to count change. It's meant to help kids be able to do math in their heads, without borrowing or scratch-paper notations or counting on fingers. What's more, he says, it has absolutely nothing to do with Common Core, which doesn't specify *how *subjects have to be taught.

**Read the rest**

# SF writing competition: a world without the Normal Curve!

Charles writes, "It's hard to imagine how we would have gotten all of the whiz-bang technology we enjoy today without the discovery of probability and statistics. From vaccines to the Internet, we owe a lot to the probabilistic revolution, and every great revolution deserves a great story!

"The Fields Institute for Research in Mathematical Sciences has partnered up with the American Statistical Association in launching a speculative fiction competition that calls on writers to imagine a world where the Normal Curve had never been discovered. Stories will be following in the tradition of Gibson and Sterling's steampunk classic, The Difference Engine, in creating an imaginative alternate history that sparks the imagination. The winning story will receive a $2000 grand prize, with an additional $1500 in cash available for youth submissions."

What would the world be like if the Normal Curve had never been discovered? (*Thanks, Charles!*)

# Art of Math (and vice versa)

Carlo Séquin is a computer science professor and sculptor at UC Berkeley who explores the art of math, and the math of art. He lives in a world of impossible objects and mind-bending shapes. Séquin’s research has contributed to the pervasiveness of digital cameras and to a revolution in computer chip design. He has developed groundbreaking computer-aided design (CAD) tools for circuit designers, mechanical engineers, and architects. Meanwhile, his huge abstract sculptures have been exhibited around the world. Visiting the computer science professor emeritus’s office is like taking a trip down the rabbit hole. Paradoxical forms are found in every corner, piled on shelves, poised on pedestals, hanging from the ceiling—optical illusions embodied in paper, cardboard, plastic, and metal.

I wrote about Séquin for the new issue of California magazine and you can read it here: Sculpting Geometry

# Sweet ukulele tribute to the largest Mersenne Prime

In the end of year episode (MP3) of the BBC's More or Less stats podcast, Tim Harford talks to a variety of interesting people about their "number of the year," with fascinating results.

But the crowning glory of the episode is Helen Arney's magnificent musical tribute to Mersenne 48, the largest Mersenne Prime ever calculated, which came to light in 2013. (Arney herself is going out on tour of the UK, for the delightfully named Full Frontal Nerdity tour)

# Rewriting sensationalist headlines for mathematical correctness

Math With Bad Drawing's "Headlines from a Mathematically Literate World" is a rather good -- and awfully funny -- compendium of comparisons between attention-grabbing, math-abusing headlines, and their math-literate equivalents.

# Vi Hart explains logarithms

The incomparable, incredible, mathematically gifted Vi Hart continues to make the world a better place for numbers and the people who love them, with a video explaining logarithms. Watch this one today (here's the torrent link).

# 88 nonillion imaginary artworks for the Tate

Shardcore writes, "The Tate recently released a 'big data' set of the 70k artworks in their collection. I've been playing with it and finding all sorts of fun to be had. The latest experiment uses the Tate data as a springboard to algorithmically imagine new artworks - 88,577,208,667,721,179,117,706,090,119,168 to be precise."

# Understanding spurious correlation in data-mining

Last May, Dave at Euri.ca took at crack at expanding Gabriel Rossman's excellent post on spurious correlation in data. It's an important read for anyone wondering whether the core hypothesis of the Big Data movement is that every sufficiently large pile of horseshit must have a pony in it somewhere. As O'Reilly's Nat Torkington says, "Anyone who thinks it’s possible to draw truthful conclusions from data analysis without really learning statistics needs to read this."

# Young brothers explain Bayes's theorem

These two young fellows are brothers from Palo Alto who've set out to produce a series of videos explaining the technical ideas in my novel Little Brother, and their first installment, explaining Bayes's Theorem, is a very promising start. I'm honored -- and delighted!

Technology behind "Little Brother" - Jamming with Bayes Rule

# Statistics Done Wrong: a guide to spotting and avoiding stats errors

Alex Reinhart's Statistics Done Wrong: The woefully complete guide is an important reference guide, right up there with classics like How to Lie With Statistics. The author has kindly published the whole text free online under a CC-BY license, with an index. It's intended for people with no stats background and is extremely readable and well-presented. The author says he's working on a new edition with new material on statistical modelling.

# A visit to the Indian temple where "0" was invented

# American education's use of "value added measures" is statistically bankrupt

American teachers are widely assessed on the basis of "value added measures," a statistical tool for analyzing the outcomes of their teaching. But as Jerry Genovese points out, this is statistically completely bankrupt -- unless you randomize your samples, you get no insight into the quality of the teaching. I asked my father, Gord Doctorow -- a mathematician, math teacher, and professor of education -- what he thought of Genovese's piece, and he sent me some great material, which you'll find after the jump.

# Statistics explained with the help of modern dance

If you're the type of person who really needs some good visuals to make a concept stick in your head, this series of YouTube videos made by the British Psychological Society Media Centre will help you remember the meanings behind statistical concepts like "correlation", "frequency distributions", and "sampling error". There are four videos in the series so far, and they do a great job of painting pictures around abstract ideas. Bonus: Soothing music.

Via Openculture

# 90 percent of Tor keys can be broken by NSA: what does it mean?

Errata Security CEO Rob Graham has published a blog-post speculating that ninety percent of the traffic on the Tor anonymized network can be broken by the NSA. That's because the majority of Tor users are still on the an old version of the software, 2.3, which uses 1024 RSA/DH keys -- and at keylengths of 1024 RSA/DH crypto can be broken in a matter of hours using custom chips fabbed at an estimated cost of $1B. It seems likely that the NSA has spent the necessary sum and sourced these chips (likely from IBM).

This isn't the same as being able to decrypt all of Tor in realtime, but it does suggest that the NSA could selectively decrypt its stored archives of Tor traffic.

However, the new version of Tor, 2.4, uses elliptical curve Diffie-Hellman ciphers, which are probably beyond the NSA's reach.

Graham faults the Tor Project for the poor uptake of its new version, though as an Ars Technica commenter points out, popular GNU/Linux distributions like Debian and its derivative Ubuntu are also to blame, since they only distribute the older, weaker version. In either event, this is a wake-up call that will likely spur both the Tor Project and the major distros to push the update.

Yesterday's revelations about the NSA's ability to decrypt 'secure' communications were taken by many to mean that the NSA had made fundamental mathematical or computing breakthroughs that allowed it to decrypt securely enciphered messages. But it's pretty clear that's *not* what's going on.