Posts tagged ‘sleep’

Mathematically Unconscious

Both of my sons sleepwalk. At least once a week, one of them will wake up an hour after bedtime, walk down the stairs, and start speaking gibberish. They have no idea what they’re saying, because they aren’t awake — even though their eyes are open. (Freaky!)

During a recent somnambulation, Alex stood at the top of the stairs. He appeared frustrated. Finally, he said:

I just need to find the numbers. It shouldn’t take long.

As you might well imagine, it’s a little scary to have your son walking and talking while asleep. The only solace is that his subconscious thoughts are about math.

I don’t sleepwalk. But I recently had a dream in which I attended a cocktail party and asked the other attendees a most unusual question:

Time Express Answer

I suspect that my 7 years as an editor and 4 years as a question writer for MathCounts are to blame, but that doesn’t make it any easier to accept.

I vividly remember a dream I had in college, on the night prior to my Linear Algebra midterm. Feeling unprepared for the exam, my nightmare consisted of two brackets pinching my head like a vice, while numbers floated past.

Lineart Algebra Nightmare

I awoke in a cold sweat at 5 a.m., and proceeded to a study carrel for more test prep.

I was happy to learn that other folks dream about math, too. While subscribed to a listserve for former instructors of the Center for Talented Youth, I received a message from Mark Jason Dominus that read, “I dreamt of the following problem while I was sleeping last night. When I woke up, I convinced myself that it was a good problem, so I’ve decided to share it.”

The volume of a 3 × 3 × 3 cube is 27 cubic units, and the volume of a 2 × 2 × 1 rectangular prism is 4 cubic units. Theoretically, six prisms should be able to fit inside the cube, with three cubic units empty. But can you arrange six 2 × 2 × 1 prisms so they fit inside a 3 × 3 × 3 cube?

2 x 2 x 1 Prism

Good luck, and sweet dreams!

February 11, 2016 at 10:46 pm 3 comments

Eat, Sleep, Do Math!

The Golden Rule of Food Shopping:

Never shop for groceries when you’re hungry.

Corollary for Mattress Shopping:

Never shop for a mattress when you’re tired.

When buying a mattress, Consumer Reports recommends that you lie down on “lots of mattresses” in the store and spend at least 15 minutes on each mattress — five minutes lying on each side, and another five minutes on your front or back, depending on your sleeping preference. I’m not certain what number is implied by “lots of mattresses,” and I’ve never been very good at math, but if you try out 6-8 different mattresses for 15 minutes each, plus some chit-chat and the requisite haggling with a salesperson, you’re trip to the mattress store is going to last at least an entire afternoon, maybe more.


This is a mattress, but
mathy folks sleep on matrices.

They also recommend that you wear loose-fitting clothes, so I donned a smoking robe and slippers. Our family then headed to Sleepy’s.

The first mattress I tested was too firm. It took far less than 15 minutes to eliminate it as a possibility.

The second mattress I tested, however, was damn near perfect. I rested on my left side for five minutes, and it felt very good. I then rolled over to my right side… and I fell asleep. Not sure what to do, my wife did what any dedicated wife would do — she left. She and the kids walked to the grocery store, and when they returned 35 minutes later, I was rousing from my slumber.

“This is the one,” I said.

“Yeah,” she said. “No shit.”

I did not need to test any more. That said, the one I liked was far from the cheapest one on the showroom floor. Consequently, haggling ensued. As I was asking for a 25% discount and the salesperson was countering with, “How ’bout I throw in a free pillow?” my sons were inspecting a poster in the store:

Sleepys Poster  Inset

The intent of the poster, of course, is to show that Americans spend 1/3 of their lives in bed. (And, implicitly, to suggest that price should not be a consideration for something you use so often.) But it caused some slight bewilderment for my sons.

Only 21.8 hours are accounted for.

If there had been no category called “Other,” it might not have been so odd. But couldn’t they have included the missing 2.2 hours in “Other”? Unless that time is spent doing something other than “Other,” but I have no idea what that might be.

If this information were represented as a pie chart, it might look like this:

Americans Time Graph

The source of the statistics, according to a footnote on the poster, is the Bureau of Labor Statistics. But that doesn’t seem true. At the top of this data table from BLS, the sum total of all activities is 24.00 hours.

My job is done here. I’m off to enjoy my new mattress. Good night.

September 28, 2014 at 7:06 pm 2 comments

Excuses Are Like Graphing Calculators…

You may have noticed that there haven’t been very many new posts on this blog recently. I apologize for that. The following flowchart — an idea blatantly stolen from Brewster Rocket — provides my excuse.

Work Sleep Repeat

Since starting a new job in March, I’ve been working 60-80 hours per week. I’m also serving as the chair of the MathCounts Question Writing Committee. Mix in the time demanded by two energetic, six-year-old boys, and, well, that doesn’t leave a lot of time for making math people laugh on the Internet. Don’t get me wrong — I’ve been funny as hell the past six months, both creating and delivering amazing one-liners. I just haven’t had time to type them up for all of you.

Not that you care about any of that. You come here for jokes, not excuses.

Here’s one about work:

The scientist asks, “Why does it work?”
The engineer asks, “How does it work?”
The project manager asks, “How much will it cost?”
The novelist asks, “Do you want fries with that?”

And here are 11 excuses I could have used, but didn’t:

  1. I created a great joke but then divided by zero, and the joke burst into flames.
  2. It’s Isaac Newton’s birthday.
  3. I could only get arbitrarily close to my computer. I couldn’t actually reach it.
  4. I had a really funny joke to share, but this blog is too narrow to contain it.
  5. I was watching the World Series and got tied up trying to prove that it converged.
  6. I have a solar-powered laptop, and it was cloudy.
  7. I wrote some jokes in a notebook and locked them in my trunk, but a four-dimensional dog got in and ate it.
  8. I was typing up some jokes when my wife brought me a doughnut and a cup of coffee. I spent the rest of the night trying to figure out which was which.
  9. I put some jokes in a Klein bottle, but then I couldn’t find them.
  10. I was too busy celebrating the coincidence of Einstein’s birthday and Pi Day.
  11. I was contemplating a formula for Phi Day, determining the first Friday the 13th in 2013, and wondering why Tau Day isn’t more popular than Pi Day.

September 21, 2013 at 9:44 am Leave a comment

Math Jokes for National Sleep Day

If you like sleep, boy, have we got some holidays for you.

Today is National Sleep Day. has a list of things to do today, and the first thing on their list — shocker! — is sleep. (Okay, technically they list “sleep in,” but doesn’t that seem obvious for this particular holiday?)

In the U.S., February 19 is National Sleep In Day; in Britain, it’s October 31. One blogger declared that May 11 should be National Sleep Naked Day.

March 3-9, 2012, is National Sleep Awareness Week, which occurs annually the week before the change to Daylight Savings Time.

And if you’re one of those folks who really likes to extend your holidays, you don’t need to limit your love of sleep to just one day or even a week. November is National Sleep Comfort Month, and May has been dubbed National Sleep Better Month.

Holy criminy! Is all of this really necessary? Luckily, mathy folks really like to sleep.

What do mathematicians sleep on?

Mathy folks also appreciate that others need sleep, too.

A math teacher is someone who talks in someone else’s sleep.

Married mathy folks have a keen awareness of how much sleep they need.

A single mathematician was asked, “If you go to bed eight hours before you have to wake up, and your girlfriend wants to have two hours of sex, how much sleep will you get?” He answered, “6 hours.”

When a married mathematician was asked the same question about having two hours of sex with his wife, he responded, “7 hours, 57 minutes. Why does it matter what she wants?”

Finally, a joke about the other meaning of the word sleep.

Wife: “If I died, would you get married again?”
Mathematician: “No.”
Wife: “Why not? Don’t you like being married?”
Mathematician: “Of course, I do.”
Wife: “Then why wouldn’t you remarry?”
Mathematician: “Fine, I’ll remarry.”
Wife: “You would?”
Mathematician: (groan)
Wife: “Would you live in our house, too?”
Mathematician: “Sure, it’s a great house.”
Wife: “Would you sleep with her in our bed?”
Mathematician: “Where else would we sleep?”
Wife: “Would you let her drive my car?”
Mathematician: “Probably. It’s brand new.”
Wife: “And would you let her use my golf clubs?”
Mathematician: “No, she’s left-handed…”

January 3, 2012 at 7:30 am Leave a comment

Trouble Sleeping?

Some researchers say that the iPad and laptops may alter sleep cycles, fooling your brain into thinking it’s daytime. Alon Avidan of the Sleep Disorders Center at UCLA said that people should just take a boring, old-fashioned book and read by a lamp. I think that’s a good idea… and might I suggest that Math Jokes 4 Mathy Folks be your book of choice?

Okay, that was a shameless plug. Then again, I’ve never claimed to be above that.

For tolerating that shameless self-promotion, you’ve earned the right to read a few math jokes about books and sleeping…

Why was the math book sad? Because it had so many problems.

Some mathematicians have become so tense recently — many of them are no longer able to sleep during seminars. 

A math professor is a person who talks in someone else’s sleep.

My apologies if that last one hits a little close to home…

May 18, 2010 at 10:52 am Leave a comment

About MJ4MF

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.

Past Posts

August 2022

Enter your email address to subscribe to the MJ4MF blog and receive new posts via email.

Join 469 other followers

Visitor Locations

free counters