## Archive for June, 2013

### Best Math Joke Ever?

If you do a search for “best math joke ever,” you’ll see that there is widespread disagreement. The following are some of what you’ll find.

The folks at Physics Forums like this one:

How does a mathematician deal with constipation?

He works it out with a pencil.

Sadly, the site failed to include this follow-up joke.

What kind of pencil?

A #2 pencil, of course.

Some folks at Yahoo Answers like this one:

An infinite number of mathematicians walk into a bar. The first one orders a drink. The second one orders half a drink. The third orders 1/4 drink. The fourth orders 1/8 drink, and so on. The bartender, a little overwhelmed, asks the mathematicians, “Hey, you guys sure you want to do this? Isn’t that a bit much?” The mathematicians reply, “Oh, don’t worry… we know our limits.”

From Mormon MD:

And the good folks at Blue Donut have taken the list of 100 funniest jokes of all-time — as compiled by *GQ* — and allow visitors to vote on them. Sadly, most of them aren’t mathy, but this one from A. Whitney Brown is.

China has a population of a billion people. One billion! That means even if you’re a one in a million kind of guy, there are still a thousand others exactly like you.

### How Much Does Your Name Cost?

Here’s a contrived yet fun math problem that I shared with my sons recently:

A local hardware store sells bronze letters. However, the letters vary in price; some are more expensive than others. When I was at the store the other day, four people purchased the letters in their names. Their names and the prices they paid were:

Aiden $491 • Ned $225 • Dane $399 • Ed $135

The price of a name is equal to the sum of the prices of its letters. The price for uppercase and lowercase letters is the same, and there is no additional surcharge or tax. How much would the following people pay to buy the letters in their names?

Edna • Ian • Nadine

Those of you who know a little algebra will have no trouble with that problem. Those of you who don’t shouldn’t have too much trouble, either.

But then, I realized I could extend the problem for some added fun. And who am I to keep fun things to myself? So, here ya go.

I saw this sign in a window the other day:

At first, I thought the store was engaging in human trafficking. But then I realized that $269 was the price for the bronze

lettersthat had been used to spell the name Eli. Inside the store was a price list for other names:

AIDEN – 491 AL – 248 ART – 267 BEA – 290 EARL – 415 DANE – 399 ED – 135 ELI – 269 FAY – 220 GABI – 289 HAL – 284 IVY – 143 JACK – 234 JAY – 232 KO – 60 KAI – 283 LEXI – 272 MAVIS – 363 MAX – 215 NED – 225 PAT – 210 PERRI – 330 QI – 93 QUIN – 199 SAMMY – 338 WILL – 243 ZENO – 243 The store didn’t have a list of prices for the individual letters, but then I realized that I didn’t need one. From the table above, I could figure out how much my name would cost.

Can you figure out how much

your namewould cost?

You can download both of these problems for use in a classroom (or at a mathy party) from the following link:

And while I don’t believe in answer keys, you can check your work by using the form found on this page.

For what it’s worth, the longest name ever — according to Wolfe + 585, Senior, who has a pretty long name himself — is Rhoshandiatellyneshiaunneveshenk Koyaanisquatsiuth Williams. Her entire name name would have cost $4,073 at this store — an astounding $2,359 for her first name, $1,119 for her middle name, and a veritable bargain at $595 for her tame-by-comparison last name. (Incidentally, this is the name that appeared on her birth certificate. As the story goes, her father later increased her first name to 1,019 letters and added an additional 36 letters to her middle name. You know… just in case the name wasn’t long or unique enough already.)

### Can You Find the Error?

I used to be the editor of the “Media Clips” column in the *Mathematics Teacher* journal. One objective of the column was to identify the use of incorrect mathematics in print. The following flyer from H. H. Gregg would have been a great example.

My favorite entry in the “Media Clips” column was a clip from the *Salt Lake Tribune* on October 11, 2002, which read:

A Salt Lake County Health Department inspector paid a visit recently [to the Coffee Garden restaurant] and pointed out that research by the Food and Drug Administration indicates that one in four eggs carries salmonella bacterium, so restaurants should never use more than three eggs when preparing quiche. [The Coffee Garden’s quiche recipe calls for four fresh eggs.]

Priceless.

Anyway, back to H. H. Gregg. The image above may be too small or blurry to identify the error, so here’s an enlargement.

I gave the flyer to my sons and told them that they could have ice cream for dessert if they were able to identify the math error. I’ll make the same offer to you — first person to post the error to the comments gets an ice cream cone from me.

### Math Teachers at Play 63

Hmm… let’s see… now where did I put my notes? I know that this is supposed to be the *Math Teachers at Play* blog carnival… but which one?

Maybe the following puzzle will help. In the grid below, do the following:

- Circle any number, then cross out the other numbers in the same row and column.
- Of the remaining nine numbers, circle one, then cross out the other numbers in the same row and column.
- There should now be four numbers remaining; circle one. Then cross out the other numbers in the same row and column.
- There should now be one number remaining. Circle it.
- Calculate the sum of the four circled numbers.

Pretty cool, huh? Try it again, and you’ll find that the sum of the four circled numbers will always be 63. Can you figure out why it works?

Ah, yes! That’s it! This is **Math Teachers at Play 63**! Good day! Welcome one and all!

You might wonder why I’d start this carnival with so many questions. Maybe it’s because 63 is the ASCII code for a question mark.

Other interesting facts about 63:

- 63 = 7 × 9.
- 63 = 2
^{6}– 1 = 1 + 2 + 4 + 8 + 16 + 32. - The record for the longest field goal in NFL history is 63 yards–kicked by Tom Dempsey, Jason Elam, and Sebastian Janikowski.
- 63 = 6
^{2}+ 3^{3}. - ‘Rule 63’ is an online adage, which states that every fictional character has a counterpart of the opposite gender.
- In Roman numerals, 63 is written as LXIII; and if you add the position of those letters in the alphabet, you get 12 + 24 + 9 + 9 + 9 = 63. It is the smallest number with this property. (Can you find the only other number with this property?)

**Pre-School**

Trying to help little kids see the fun and usefulness of math, **Beanie N Us** shows her daughter Learning about Numbers at the Car Park and having Fun with Math.

**Elementary School**

At the **New Hope Elementary School**, kids of all ages do M&M Math to learn about graphs, measurement, and area. Yum!

Fraction Folding, Discovery Learning is the first in a series of 16 blog posts that documents what a fourth-grade teacher at the **Fourth Grade Studio** did to help students develop conceptual understanding of fractions.

**Navigating by Joy** shares A Living Maths Approach to Angles using the book *Sir Cumference and the Great Knight of Angleland* and also shows how to have Fun With Tessellations.

When the **Math Mama Writes**, you better listen, especially when she’s questioning how and why we teach vocabulary in Writing, Vocabulary, and Teacher Inquiry.

**Middle School**

Offering straightforward and practical advice, **The Numerist** explains How to Write an Equation of the Line.

Who doesn’t love a story about student success? **4mulaFun** shares such a story from a lesson that has students Reviewing Proportions with WKU. (Don’t know WKU? Neither did I! Read on.)

**Miss Math Dork** shares One of Her Favorite Activities for teaching measurement to middle schoolers, which is sure to become one of your favorites, too!

**High School**

Watch what happens when **Mr. Chase** alternately adds and multiplies in Arithmetic-Geometric Hybrid Sequences.

In** **Probabilities in a Painted Cube, **Cut the Knot** examines solutions to a problem about painting and cutting a larger cube into unit cubes and then considers the historical problem of constructing a line that halves the area and the perimeter of a triangle in Area and Perimeter Splitters in a Triangle.

**Math and Multimedia** share 5 Fascinating Facts About Triangles That Will Surprise You.

Did you know that a Quadrilateral with Congruent Opposite Sides is a Parallelogram? **Proofs from the Book** will show you why.

**Let’s Play Math** tells us How To Master Quadratic Equations, with some assistance from James Tanton’s G’day Math Courses.

**Potpourri**

Are vectors too tough for mental math? Not according to **White Group Maths**, whose Vectors Mental Quiz demonstrates all the stuff you can calculate in your head without reaching for a computing device.

A mom and her kid at **Moebius Noodles** used concept maps to create *Free To Learn* by Peter Gray: Review and Infographics.

Charlotte Mason and Louis Benezet’s Thoughts on Math are documented by **Triumphant Learning**.

### Best Use of Math Textbooks

I had an ergonomics consultation last week, in which the specialist suggested that my monitor was too low. She said that I needed to raise it 6-8″ to be at an appropriate height, and since it will take more than a week to get the monitor stand, she had an alternate solution:

I have over 50 textbooks on my bookshelf. I chose five that seem to be more effective at supporting my monitor than math education.

My colleagues are getting a good chuckle out of this.

### Math Jokes for National Doughnut Day

Today is National Doughnut Day, and if you need your fix, *Time* reports that free doughnuts are available from Dunkin’ Donuts, Krispy Kreme, Tastykake or Winn Dixie.

At MJ4MF, we can’t let this day pass without telling the obvious joke…

A topologist is a mathematician who can’t tell a coffee cup from a doughnut.

And the modification…

How many topologists does it take to change a light bulb?

Just one. But what’ll you do with the doughnut?

To help you celebrate, here’s a doughnut-related math problem.

Several years ago, Dunkin’ Donuts ran a commercial bragging about how picky they were. The commercial stated:

We reject more than one million pounds of coffee beans a year.

Sure sounds impressive, doesn’t it? But how picky are they, really? Do a back-of-the-envelope estimate, and I think you’ll realize that they’re not all that picky after all.