Posts tagged ‘cubes’

Math Dreams

“I can’t get the numbers to stop.”

That’s what Eli told my wife tonight when he woke from a bad dream.

Number DreamI once had a dream where I was afraid of numbers, too. During the week leading up to my midterm in Linear Algebra, I was reviewing problems from old exams. Though I thoroughly understood all that had been covered in class, and though I was able to complete all the exercises from the textbook with aplomb, I was only getting about 25% of the questions on the old exams correct.

It was freaking me out, and the night before the exam, I went to sleep very nervous.

My sleep was broken by a nightmare in which numbers were flying past my head like cannonballs from a numerical howitzer. They were coming from every direction. To make matters worse, my head was being squeezed by the brackets of a matrix as if it were in a vice.

I woke in a cold sweat. It was 5 a.m. Too anxious to sleep any more, I went to a study carrel in the library where I read and re-read the textbook and continually tried the problems from the old exams. I skipped my morning classes and studied for five straight hours. Yet I was still only able to get a quarter of the problems correct.

The midterm was at 12:30 p.m. At 11:55 a.m., I saw a woman from my class. Though I had never spoken to her before, I approached her and said, “Excuse me, aren’t you in Dr. Sibley’s linear algebra course?”

“Yes,” she replied skeptically.

“Would you mind helping me?” I asked, embarassed by the question.

“Uh… sure,” she said.

I asked her a few questions about the topics we had covered. She confirmed that I understood the material correctly. “So why am I missing so many of the questions from the old exams?” I asked rhetorically.

She took a look at my work and confirmed that it, too, was correct. Then she revealed the punch line: The professor had given us a packet of six exams, and the answer keys for all six exams were copied onto a seventh sheet. But the answer keys and the exams were not in the same order — each answer key had to be matched to an exam by noting the semester and date on each.


I was relieved. Yet frustrated. I managed an 85 on the midterm… yet I’m certain I would have aced it had I gotten a good night’s sleep.

Mark Jason Dominus has much better math dreams than I. He posted the following problem to the mattababy listserv. He claimed that it came to him in a dream; when he woke, he thought it was still a good problem, so he decided to share it.

The volume of a 3 × 3 × 3 cube is 27 cubic units, and the volume of a 2 × 2 × 1 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?

Friends of mine who taught at the Center for Talented Youth claim that M. J. Dominus would often arrive late to the evening study sessions. As the story goes, he would take naps after dinner… if his alarm sounded while he was in the middle of a math dream, he would shut off the alarm and return to sleep so he could finish whatever mathematical proof his subconscience had been working on.


What’s the scariest or coolest math dream you’ve ever had?

January 9, 2013 at 10:18 pm 1 comment

Reap What You Sow

Yesterday, our home owner association paved and painted the parking lot behind our townhouse. My twin three-year-old sons, Alex and Eli, were fascinated by the large, white numbers that now adorn each parking spot. They counted all of the numbers out loud, which ranged from 16 to 37. “Where is 1?” Alex asked.

The lot behind our house is Parking Lot B; spaces 1‑15 are in Parking Lot A. I probably should have explained this to him, but instead I just said, “There’s no number 1 in our parking lot. This lot begins with number 16. Isn’t that an odd number with which to begin a parking lot?”

He responded, “No, daddy. Sixteen is an even number, actually.”

I suppose that’s what I deserve for teaching my kids about parity before their fourth birthday.

This incident reminded me of the following joke, which appears in a slightly different form in Math Jokes 4 Mathy Folks:

A teacher asks her class, “How can you divide 25 sugar cubes among 3 cups of coffee so there is an odd number of cubes in each cup?”

Bekkah responds, “Put one in the first cup, and put 12 in each of the other cups.”

“But 12 isn’t an odd number,” the teacher replies.

“Sure it is,” Bekkah replies. “Twelve is a very odd number of sugar cubes to put in a cup of coffee!”

This joke is typically told so that the teacher asks students to divide 14 sugar cubes into 3 cups of coffee, and the student says to divide them as 1, 1, and 12. I never liked that version, though, because the problem as posed by the teacher is unsolvable — that is, there is no way to divide 14 sugar cubes such that there is an odd number in each cup. Yes, I know it’s only a joke… but I like to think that a teacher would only ask a question that had a solution.

August 12, 2010 at 6:31 am 3 comments

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.

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