A lot of people will be surprised when I can't do some base calculations quickly in my head, and then will be equally surprised when I can do others almost instantly. The fact is that lots of mathy people aren't that much more skilled at... errr... numbers, than most, but rather are just more familiar with them. I know you're never supposed to reveal your tricks, but this is just a bit of insight into how certain problems have quick shortcuts.

Example:

15*39. On the surface this looks like any old two digit multiplication. But to a math major who is used to factoring and such, it instantly becomes 15*(40-1) = 4*15 *10 - 15 = 600 - 15 = 585. Each step is very simple and can be done very fast, but you don't necessarily see the shortcut if you don't work with expressions often.

Example:

16 * 48. Again, this becomes 16 * 16 *3, and any math major worth his salt knows his squares up to 25, just because he's done them so often. So 16 *16 * 3 = 256 * 2 = (250 +6) * 3 = 750 +18 = 768. Again, just three instantaneous steps, if you see them.

Counterexample:

32 * 37. This I would probably just do longform in my head, which I am bad at. No immediately obvious trick (to me at least) so I do the normal three multiplications and one addition.

Example:

Is x<100 prime? Well, I figured out a while ago that you only have to look for factors less than the root of x, so less than 10. This is because if z divides 100, and z is greater than 10, then z*10>100, so z's factor pair (that is, 100/z) must be less than 10. So to find z, you just have to find its pair.

Further, even x's are obvious not prime, and odd numbers are only even the product of two odds, so you only have to look for odd numbers under 10: 3,5,7,9. On top of that, the numbers divisible by 5 and 9 are immediately obvious. So all we have left is to check if a number is divisible by 3 or 7. Well. a number is divisible by 3 if and only if the sum of the digits is, so that is a quick test. That leaves as the only real test divisibility by 7. Thus the question, 'is 83 prime,' can be answered just by noticing that 8 is not divisible by 3, and 83 is 13 more than 70. So pretty much this entire paragraph is already coded into my thought process, which is why the answer will come pretty quickly. The same holds true for most numbers less than 200, you just have to test for 11 and 13 also, and beware of the dreaded 119, which should totally be prime.

http://www.ushmm.org/

Notice any language missing?

Overheard in the hipster coffeeshop I'm in:

"Hey do [ridiculous sounding band] have a CD?"

"Yeah, they're in DC."

"No, a CD."

"Yeah, DC."

"Nonono, do they have a Ceeeee Deeeeee out?"

"Well I guess technically they're in Maryl.... oh. You mean an LP?"

"Yeah. A CD."

"Don't be so 90s."

Also, apparently hipsters have taken over plaid, so now I can't wear my flannel. I hate them so much.

Airport musings:

Cute little girl during the takeoff from Sitka:

“My favorite color is every color in the world! What is yours?”

“Grey”

“Grey is not color!”

“Why not?”

“Because colors are pretty!”

“You know what makes me really scared?”

“What?”

“Airplanes.”

So as I was walking through the Seattle-Tacoma airport at 3am I realized that when I'm really tired, I start mumbling to myself like a crazy person. Upon further reflection, I remembered that even when I'm not that tired, I often mumble to myself like a crazy person. Then I realized that I was in fact mumbling to myself like a crazy person about mumbling to myself like a crazy person, and at that exact moment, in an otherwise empty terminal, I passed another guy who was mumbling to himself like a crazy person. We made brief eye contact, exchanged knowing glances, and went our separate ways.

Among the crazy-person thoughts that ran through my head during the 3 to 6am sleepless block:

“I wonder when Starbucks wakes up.”

“If I hit the newscaster in the mouth, will it mute all the tvs?”

“4 times 15 is.... is... is.... 45? Yeah! Yeah? Yeeeeeeah.”

“You can brush your teeth with soap, right?”

“No.”

“Well soap is clean.... and I want my teeth clean... I can totall... no that's a bad idea.”

So there was another potentially adorable little girl (I'm really not that creepy, I promise) in front of me on the way to Minneapolis. She had a pastel purple carry-on, and as she lifted it up to her mom, I craned my neck to see which Disney Princess she claimed allegiance to. Unfortunately the bitter truth revealed itself when I saw that it was not in fact a Disney bag, but a Bratz bag. Instantly, all potential for amusement was sucked out of my mind and every otherwise darnest thing she said was stupid and annoying.

“We can't take off because I don't have a carseat!”

“That's because you're on an airplane, dumbass.”

“I I I don't know why planes are so big and still can fly?!”

“Pressure differentials, airspeed, and wing loading. Look it up, little ingrate*.”

*There are lots of ingrates in The Count of Monte Cristo."

Even though I'm usually pretty good at suppressing sappiness, it was hard not to feel a strum of nostalgia as we took off. The Three Sisters moved out of their usual alignment; Arrowhead jumped out from behind Verstovia; and I swear I saw the sun glint off of the Gavin shelter as we flew past the the four peaks of Harbor.

Sitka is without question one of the prettiest places I've ever been. Even the most skilled artist would not add or subtract a single tree from her artless grandeur. Very rarely does Beauty reveal herself so readily and openly, even on the drive to the bank or the walk to work, as she does on that tiny island in southeast Alaska.

This blog post paid for by the Sitka chamber of commerce.