If Vanguard charges .15% and Schwab, .03%, Vanguard’s fee is five time as much or 400% higher. They charge 12 basis points more. (A basis point is .01%, used in the financial industry). Schwab?
Scary Data on Middle School Math Teachers
Disclosure – I work part time in a High School, in the Math Department. I am an in-house tutor. I have my initial teacher’s license for both middle and high school math. When I took one of the exams, there was a person on line who had the look of a scared student about to take an SAT exam. I asked her if she was okay, and she told me that she had failed the middle school math exam. This is the data, although not the same year. Still relevant.
It starts for me with the fact that a teacher looking to add middle school math to their credential fails this exam 1/3 the time as a first time tester. If We subtract “First” from “All”, we find that 82 people took it their second (or more) time, and of those, 27 passed. Consider, the exam is graded on a scale of 100-300 (that, itself is strange to me), and 240 is passing. 70%. A student that passes their class with a 70% is not really ready to stay at that level the next year. You can see that 275 is a full standard deviation above the mean. 1 in 6 middle school math teachers has gotten an 88 or higher on their licensing exam. For me, this raises new and troubling questions.
Dividing is Tough
This is a snapshot of a Tweet in my feed. Painful to read for a few reasons, the grammar, of course, is the least of it.
Let’s start with US population. 327.2 million as of 2018. If we agree it’s close to 333 million, that’s 1/3 of a billion. In other words, $3 per person adds to $1B dollars. In which case, $460B isn’t quite $1400 per person. But, of course, even Jeff Bezos, the US richest person, is ‘only’ worth $114B. And Bloomberg might have spent $460M, not billion. Bloomberg is worth about $64 billion, and that divides to a number closer to $200 per person.
This, to me, is classic innumeracy, the inability to think about how absurd the tweet above was, before hitting “send”. As far as the grammar goes, I blame J. Geils for this one.
Up to 80% savings?
I continue to marvel at how people in advertising have no idea how percentages work. When a company advertises that they can save you “up to 80%” but then show an example of a customer who owed $977,100, but paid the IRS just $1000 (let’s be clear, the savings was just under 99.9% here), you know we have an issue.
By the way, if anyone is reading (?) I’d love you to send an example of your own. Leave a comment, and I’ll get right back to you.)
Magazine Subscription Deal?
You can call this a typo, if you wish. Bad copy editing. Or a sign the world will end just over halfway into next year. In which case, I’d expect to pay less for the 10 issues of Forbes I’d get in year 2.
If you are visiting today from Stack Exchange, this blog was inspired by the question “Examples of Innumeracy“. If you have an example for me to add here, please leave me a note!
Broker Math
Disclosure – I have investments with both Vanguard and Schwab, they are both good companies. I don’t blame Schwab for this ad, odds are good that they used an outside firm. One that should be fired.
Do you see where they went wrong? .03 is 80% less than .15. But the reverse isn’t true, .15 is five times .03, not “Nearly 80% more.”
Say, we have 2 dogs. Mine is 10 lbs, yours is 20 lbs. Mine is 50% the size of yours, but yours is not then 50% larger. He’s twice the size. This is math we expect our kids to learn in grade school, well before high school.
And for the record, Vanguard charges me .02% for the S&P fund in my 401(k) retirement account. The ticker is VIIIX, look it up.
Gold Seller doesn’t know percentages
The Globe ad was just one example of how ad writers can be clueless. Here’s another example. I scanned this from an advertisement from a company trying to sell you gold coins. Set aside the timeframe of this ad, by the end of 2016 the S&P had recovered so that 2000-2016 would have shown growth to $21,000, otherwise known as +110%.
Look at the percent growth the ad shows for Real Estate and Gold. $10,000 to $26,065 is “Up $16,065” which, from a starting point of $10,000 is +161% (rounding up). Not +260%. If gold was worth just $11000, would they have advertised “Up 110%”?
I can’t help but wonder what the qualifications are for ad writer at these companies.
The Mother of All Math Errors
First, a disclaimer. War is awful. As is people dying. I won’t get into the politics of recent events, just the math.
It’s time to call out USA Today for what it is. Not quite fake news, the right words might just be “a mathematical abomination.”
The graphic might be visually pleasing to some. “Hey, the bomb was 5 times the height of a man.” Ok. Then, the comparison to the bomb the US dropped on Hiroshima. The text suggests this bomb was more than 2/3 as powerful as the Hiroshima bomb. And that text made it past a number of employees at USA Today. But not one of them had the mathematical gut to realize something was wrong. The Hiroshima bomb was an atom bomb. Its blast was equal to not 15 tons of TNT, but 15 kilotons, or 15,000 tons. The Atom bomb was more than 1300 times as powerful as the bomb just dropped in Afghanistan.
USA Today deserves their own category for innumeracy. This is typical for the paper.
90% off!
This speaks for itself. “Was $235” and “90% off” makes the math easy. 10% is left. $23.50. If they rounded to $24, I’d cut them some slack. $29 is, well, 87.66% off. 
2016 12 08
Ha! That’s today’s date. My daughter tells me this is not remarkable. That I seem to come up with an observation like this pretty often. Well, to be fair, I was pretty excited when it was 3/14/15 especially the two times the clock showed 9:26:53. But that was a year and a half ago.
Let’s see when my next date of interest will be. Stay tuned.