## Posts tagged ‘coins’

### Don’t Get Mad, Get Equal

The title of this post is a modification of a common idiom. It doesn’t make much sense, but if people are allowed to use even when they mean equal, then vice versa.

A math terminology debate over these two words occurred in our house yesterday.

While walking my dog, I found a shiny, new penny. When I got home, I told my sons that whoever guessed the item I found could have that item. To my dismay, my mother-in-law, father-in-law and wife started making suggestions. “Maybe it’s a penny,” my wife suggested. “Or a quarter,” said my mother-in-law. “Or a dime,” said my father-in-law. I looked at my dog. C’mon, boy, you’re the only one who hasn’t said anything. Why don’t you suggest that it could also be a nickel and make this game completely devoid of fun, I thought.

But kudos to Eli for what he did next. “Is it a coin?” he asked, and I could almost see his five-year-old brain thinking that this would make him a winner no matter which of the suggested coins it was.

“It sure is!” I said, beaming, and handed him the coin.

We play games like this all the time, and each of my sons wins in roughly equal proportions. But upon seeing Eli receive a penny, my mother-in-law must have sensed favoritism. She pulled out her coin purse and handed some coins to both boys. When the dust settled, Eli had two nickels and three pennies, but Alex had just one nickel and three pennies. Alex asked why he had received fewer. It was just an oversight, and Grandma gave him another nickel.

“Now we have an even number of coins,” Eli said.

“Actually, you have an equal number of coins,” I corrected. “Five isn’t an even number.”

“Oh, come on,” said my mother-in-law. “They’re five years old.”

“I’d rather them not use math words incorrectly,” I said. “You’d correct them if they called a firetruck an ambulance, wouldn’t you?”

“That’s different,” she said.

Only because you know the difference between a firetruck and an ambulance, but not between even and equal, I thought. But I didn’t say anything.

As it turns out, the Google dictionary lists equal as a synonym for even. In that case, however, equal means being in equilibrium or balanced, not having the same number or value, so there is a subtle distinction. Then again, the Google dictionary also gives regardless as the definition for irregardless, which isn’t even a word, and if it were, it should mean the opposite of regardless, right? The work of lexicographers often reflects how we speak and not how we ought to speak, so it won’t be long before equal and even have the same definitions.

What do you think? Are even and equal synonyms? Are there other math words that are used interchangeably but shouldn’t be?

My mother-in-law and I often have these little exchanges, but for the most part, we get along well. She is an exceptionally wonderful grandmother, she is generous and kind, and her penchant for dark beers makes her an instant friend. I love her dearly.

Yet these debates make me realize why other folks disparage their in-laws. If my mother-in-law and I had these debates and she weren’t otherwise wonderful, I might speak ill of her, too. And then I might make math mother-in-law jokes like the following:

I’ve got nothing against polygamy. I just don’t know how one man could tolerate that many mother-in-laws.

Or this one from comedian Les Dawson:

My mother-in-law caused an argument in a pub, and a half dozen men dragged her to the floor, screaming. The barman turned to me and asked, “Aren’t you going to help?”

“Nah!” I said. “Six should be plenty!”

Not long ago, I was told that I only had three months left to live. So my wife and I moved in with my mother-in-law, knowing it would feel a whole lot longer. One night, the three of us sat down for dinner, and my wife opened a bottle of wine. My wife read from the label, “Full-bodied and imposing, with a sharp bite and a bitter aftertaste.” She took a sip. “I think that’s a perfect description!” she said.

“Me, too,” I added. “But how does the winemaker know your mother?”

### Hiring, Firing, and Flipping Coins

Tomorrow, I become the Director of Mathematics at Discovery Education, and I am slated to spend five hours with the Human Resources department, filling out paperwork and such. By the end of it, I suspect I’ll feel like Arlo Guthrie in Alice’s Restaurant:

…the sergeant came over, had some paper in his hand, held it up and said, “Kids, this piece of paper’s got 47 words, 37 sentences, 58 words, we wanna know [blah, blah, blah, blah],” and he talked for 45 minutes and nobody understood a word that he said, but we had fun filling out the forms and playing with the pencils…

I do not mean to disparage Discovery’s HR department, but my new boss has described this orientation as “a test of attrition.”

The following two days will be less bureaucratic but similarly intense. As I am the first employee hired for “the math team,” it will be my job to hire others, so my second and third days at Discovery will consist of six interviews with potential math specialists. Six! Hopefully it won’t go like this:

Three candidates are being considered for a job. The first candidate, a pure mathematician, steps into the interview room. The interviewer asks just one question, “What is 1/3 + 2/3?”

Without hesitation, the pure mathematician answers, “1.”

An applied mathematician enters next and is asked the same question. He takes out his calculator, punches some buttons, and announces, “0.99999999.”

Finally, a statistician enters the room and is asked the same question. “What is 1/3 + 2/3?” the interviewer asks.

The statistician responds, “That depends. What would you like it to be?”

My worry with so many back-to-back interviews is falling into the Gambler’s Fallacy. Just as a gambler incorrectly assumes that a string of successive heads must eventually be broken by tails, interviewers often believe that a string of successive weak candidates must eventually be broken by a strong candidate. In a recent interview with Steve Inskeep on NPR (Deciphering Hidden Biases During Interviews), Shankar Vedantam said…

…interviewers add the equivalent of two years of job experience to the last candidate in a row, who is weak, in order to break the streak.

Vedantam went on to say that Uri Simonsohn from the Wharton School of Business thinks interviewers should…

…have a spreadsheet where they can see all the candidates they’ve interviewed, not just on that one day, but over several days. And when you step back and actually say, “Yeah, there are an equal number of strong and weak candidates,” even though you may have the streaks of four or five really strong or really weak candidates in a row.

And who am I to argue with advice like that?

For you, I offer the Clusters spreadsheet, which can be used to simulate 100 coin tosses. Press F9 to generate a new set of tosses. The spreadsheet will then calculate the number of heads, the number of tails, and the longest run of either type. It shows that unexpected strings of consecutive heads and tails occur, but over the long run, the number of heads and tails are roughly equal, just as the number of strong and weak candidates who are being interviewed.

Just between you and me, though, I’m hoping for a slight imbalance toward the strong end.

### Retail Tales

In tough economic times, lots of folks are counting quarters and pinching pennies. To attract new customers, retailers are offering significant discounts.

• A local bookstore is having a sale: All Math Titles, 1/3 Off. So I picked up a copy of Gödel, Escher.
• Skate Charm Insurance is offering fire-and-theft policies at rock-bottom prices. When asked how they could offer them so cheap, the actuaries responded, “Who would steal a burnt car?”
• Grocery stores in Northern Virginia are promoting lite beer as a good deal, because it has 20% fewer letters than light beer.
• A local gas station recently switched to metric, and I somehow feel better paying \$1 per liter instead of \$3.78 per gallon.

Nobody likes change, except a kid with a piggy bank.

What coin doubles in value when half is removed?
A half dollar.

Doc: Give me an update on the boy who swallowed four quarters.
Nurse: No change yet.

In the shameless plug department: NCTM members get a 25% discount off the retail price of Math Jokes 4 Mathy Folks at NCTM conferences, and everyone else can save 24% by buying from Amazon.

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

## MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.