Maths teacher Ben Orlin has a clever, funny, and informative blog. Also, Donald Trump’s math doesn’t add up. (More)

Squirrels love mathematics, probably because we invented game theory. Or maybe I have that backward. Either way, I was delighted to find Ben Orlin’s Math With Bad Numbers blog. The drawing in today’s logo is his, and I’ll spare you the eyestrain. It says this:

“Lesson Plan” is an oxymoron.

I found his site through this Washington Post column by Aaron Blake, which I found while reading another story that I don’t even remember. Anyway, I followed Blake’s link to Orlin’s drawing of how mathematicians see probability

… as compared to how other professions see probability:

He has several others too. They’re delightfully accurate, and they illustrate an important point: amateur expressions of probability are often woefully inept. Or, depending on the profession, conveniently vague:

Orlin’s essay on why he stopped doing interviews for Yale is bitingly accurate, and his essay on exponents presents a subtle but essential mathematical concept brilliantly.

Oh, and he’s a “maths” teacher – not a “math” teacher – because the British keep the plural when they shorten the word “mathematics.” Orlin isn’t British, but he teaches there now …


“That’s not the answer to anything”

… where Donald Trump is not and will never be more than a celebrity. Well, he won’t be anything more than that here, either, but in the meantime he’s spreading an absurd mathematical mistake:

At the unveiling of his tax plan Monday, Donald Trump deployed a thoroughly debunked statistic about the American jobs market. The real unemployment rate, he claimed, is somewhere near 42 percent.

What about the the official unemployment rate, which the Bureau of Labor Statistics said was 5.1 percent for last month? That number, Trump said, “is the biggest joke there is in this country.”

In August, Trump made the same statement to Time magazine. “I saw a chart the other day, our real unemployment – because you have ninety million people that aren’t working. Ninety-three million to be exact,” he said.

It’s true that there are (roughly) another 93 million Americans over age 16 who are included in the unemployment data. But who are they, exactly?

So almost 60% of those 93 million Americans are under 25 – most of them attending high school or college – or they’re retired. And most of the rest are stay-at-home spouses, or disabled adults who can’t work.

Yes, there are “discouraged workers,” roughly 624,000, according to BLS survey data, who aren’t counted in the commonly-cited U3 unemployment rate – currently 5.1% – because they’ve given up looking for work. But they are counted in the U4 rate of 5.5%. The U5 rate of 6.2% adds “marginally attached” workers who look for work occasionally, but not every month. And the U6 rate of 10.3% includes part-time workers who would like to find full-time jobs.

As the Washington Post’s Jeff Guo concludes:

All of these numbers present a useful way of thinking about those who want to work in America.

The number 42 percent? That’s not the answer to anything.

And neither is Donald Trump.


Photo Credit: Ben Orlin (Math With Bad Drawings)


Good day and good nuts