Monday, February 5, 2007

Why, of all the numbers in the range 1 through 20, do we like 17?

Dave Munger over at Cognitive Daily has posted the results of his poll asking readers to pick a number between 1 and 20. The number 17 was picked almost 18 percent of the time, compared to the expected 5 percent from his sample of 347 responses. Comments on the results included the following attempts at explaining why humans seem to prefer 17:

Austin wrote:
As someone who chose the number 17 perhaps I can offer my personal insight - I was looking to select the most unlikely number (sorry!). In this sense i wonder if this is actually a measure of perceived least common number rather than random selection - there is a body of research about the ability to actually generate random numbers being very difficult for human subjects (methinks Sallice, T).
Michael said:

I think the answer is bisection. Our minds first go to (20+0)/2=10 but then we think, oh that's too obvious. So we next choose (20+10)/2=15. Nope, still too obvious. Then we go (20+15)/2=17.5, round it to 17 and the loop ends, because we are getting too close to 20 to be comfortable. Nonsense, probably, but that is what comes to mind...

Craig Pennington wondered,

...if the fairly uniform distribution of n*7 modulo 10 (7, 4, 1, 8, 5, 2, 9, 6, 3, 0) has anything to do with the popularity of 7 and 17. I'd bet (x*10)+7 is preferred for most "random" ranges (more so for primes -- and just under 1 in 4 primes less than 100 is 7 modulo 10.)

i wonder what would be result of an equivalent experiment carried out on some of our primate cousins? Experiments do suggest that rhesus monkeys, at least, do posses the capacity for "spontaneous number representation."

Sunday, February 4, 2007

Stunning facts

Did you know that 111,111,111 x 111,111,111 = 12,345,678,987,654,321? It is number 87 on the Interesting Real Facts site, where i also discovered that:
  • On average, 12 newborns will be given to the wrong parents daily.
  • Leonardo da Vinci could write with one hand and draw with the other at the same time.
  • The average person's left hand does 56% of the typing.
  • You burn more calories sleeping than you do watching TV.
There are 104 other "Strange but true facts"on the page. Enjoy!

Thursday, February 1, 2007

I support the Math Insurgency

i have just found out via a link at Let's Play Math about the math insurgency that seems to be brewing in Washington state. It is led by a group called Where's the Math whose mission is
To ensure that all Washington State students have an equal opportunity to compete successfully in the international economy by aligning Washington State math standards, assessments and curricula to those of top performing nations in the world.
They are concerned that mathematics achievement in America is far below what it should be and seriously lagging most other industrialized countries in the world. One of their members, Hugh Taylor of Washington state laments that U.S. math education in general is "uniquely unsuccessful."

While sympathizing with these concerns, it is worth noting the global dimensions of the problem: For students in many 'developing countries,' poor or mediocre math education--and thus achievement--is the norm. That is why i hope the math insurgency succeeds in the US, and spreads to the developing world.