Why Thomas Jefferson ditched his newspaper subscriptions in favor of Newton, Euclid, Tacitus and Thucydides

I don't use Twitter for my own commentary but maintain an account with which to follow others. One feed I enjoy immensely is "On This Day in Math," which today brought us this tidbit: "1812 Thomas Jefferson writes [to] John Adams 'I have given up newspapers in exchange for Tacitus and Thucydides, for Newton and Euclid;...'" Oh, to be afforded such a luxury! For now, though, your correspondent regrettably must remain ensconced in daily affairs.

Still, to honor TJ's late-in-life liberation from what must have been a life-long newspaper addiction, those of you who have too long neglected your Newton and Euclid ought to add to their new year's resolutions spending spare time watching Vi Hart videos (and rewatching them, perhaps with assistance from Sal Khan, till you thoroughly understand them). I had occasion over the summer to spend time re-upping my basic geometry and trig skills and looking at the material as an adult with an eye toward utility on my own projects. That turned out to be an entirely different and far more productive experience than slogging through geometry and trig texts in high school.

More math tricks

Here are several items/links I wanted to remember as I try to teach kids in the Blanton Elementary math pentathlon team a few tricks to make (dreaded) multiplication less scary.

• How to count up to 99 on two hands.
• Finger tricks for multiplying (a trick for multiplying by nine [at least, 9x 1-10] on your fingers, and two tricks for multiplying one and two digit numbers on your fingers).
• Ethiopian multiplication (ridiculously cool).

The above are taken from a cool blog series on 25 (or 26?) different ways to multiply.

Three random math and science items I want to remember

A comet slingshot around Mars later this month and NASA has a remarkable number of ways they're gathering data from the event. Check out the graphic here. Here's another depicting its trajectory.

I didn't know a "blood moon" was a real thing until the recent eclipse. I was up during the time frame but there was too much cloud cover to see the moon from my back deck. Some of the pics from locales were it was visible were pretty spectacular. Apparently the earth's atmosphere acts as a lens to create the refracted red effect.

How many ways do you know to multiply? This person has counted 25, at least. I also enjoyed this blog post on the history of division. I'm coaching 4th and 5th graders on an elementary school math pentathlon team and am teaching them to add, subtract and multiply from left to right in their heads as opposed to right to left as one does when performing sums on paper. They think one different way to multiply is too much; 25 would (will) blow their mind.