# Reblog: Calculus Tidbits

[Feature photo above by Olga Lednichenko via Flickr (CC BY 2.0).]

This week I have a series of quotes about calculus from my first two years of blogging. The posts were so short that I won’t bother to link you back to them, but math humor keeps well over the years, and W. W. Sawyer is (as always) insightful.

I hope you enjoy this “Throw-back Thursday” blast from the Let’s Play Math! blog archives:

## Finding the Limit

Eldest daughter had her first calculus lesson last night: finding the limit as delta-t approached zero. The teacher found the speed of a car at a given point by using the distance function, calculating the average speed over shorter and shorter time intervals. Dd summarized the lesson for me:

“If you want to divide by zero, you have to sneak up on it from behind.”

## Harmonic Series Quotation

This kicked off my week with a laugh:

Today I said to the calculus students, “I know, you’re looking at this series and you don’t see what I’m warning you about. You look and it and you think, ‘I trust this series. I would take candy from this series. I would get in a car with this series.’ But I’m going to warn you, this series is out to get you. Always remember: The harmonic series diverges. Never forget it.”

—Rudbeckia Hirta
Learning Curves Blog: The Harmonic Series
quoting Alexandre Borovik

## So You Think You Know Calculus?

Rudbeckia Hirta has a great idea for a new TV blockbuster:

## Common Sense and Calculus

And here’s a quick quote from W. W. Sawyer’s Mathematician’s Delight:

If you cannot see what the exact speed is, begin to ask questions. Silly ones are the best to begin with. Is the speed a million miles an hour? Or one inch a century? Somewhere between these limits. Good. We now know something about the speed. Begin to bring the limits in, and see how close together they can be brought.

Study your own methods of thought. How do you know that the speed is less than a million miles an hour? What method, in fact, are you unconsciously using to estimate speed? Can this method be applied to get closer estimates?

You know what speed is. You would not believe a man who claimed to walk at 5 miles an hour, but took 3 hours to walk 6 miles. You have only to apply the same common sense to stones rolling down hillsides, and the calculus is at your command.

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# Every Day Is Math Day

Happy 11/12/13, otherwise known as “tenty-one, tenty-two, tenty-three.”

Do your young children have trouble counting in the teens? Try making up Funny Numbers to help them! It’s a great habit to develop, because Funny Numbers will come in handy as mental math tools throughout their school math career.

If you’d like to make your own Happy Math Day post, check out the instructions here: Every Day Is Mathematics Day. And please share a link in the comments section below — I’d love to see what math holiday you invent!

Update: The numbers 11, 12, and 13 form an arithmetic progression. If that sounds too scary for your kids, check out Patrick’s bedtime math discussion Making Progress, Arithmetically.

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# Math That Is Fun: Infinite Primes

Oh, my! Ben Orlin over at Math with Bad Drawings just published my new favorite math proof ever:

I had a fight with Euclid on the nature of the primes.
It got a little heated – you know how the tension climbs.

It started out most civil, with a honeyed cup of tea;
we traded tales of scholars, like Descartes and Ptolemy.
But as the tea began to cool, our chatter did as well.
We’d had our fill of gossip. We sat silent for a spell.
That’s when Euclid turned to me, and said, “Hear this, my friend:
did you know the primes go on forever, with no end?” …

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# Happy Square of a Square Day

### In Response To

Make your own “Happy Math Day” sign:

Here’s a fun activity for any age that will encourage your children to play with numbers:

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# Have a Mathy Thanksgiving Dinner

Professional Mathemusician Vi Hart is back with more mathematical holiday fun. Enjoy!

### Thanksgiving Turduckenen-duckenen

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# New Math by Tom Lehrer

While I was working on the next post in my PUFM Series, I stumbled on an old favorite video. Since I couldn’t think of an excuse to use it in a post about multiplication, I decided to share it today. Enjoy!

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# A Bit of Arithmetic Fun

Singing Banana (James Grime) recorded this video at the Mathematical Association annual conference dinner, 2011. I’ve shared it before, but that was over a holiday weekend, so many of you may have missed it. It relates, in a way, to our PUFM lesson this week.

Enjoy!

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# Super Bowl XLVI Math Worksheet and Football Comic

Lance Friedman of MathPlane.com has posted two bits of fun in honor of Super Bowl XLVI. (Click the images to go to Lance’s site.) And if you’re a homeschooler, Currclick is offering a Super Bowl Mini-Helper free this week.

# Halloween: The Math of Zombies

A new video from SingingBanana:

# Square One TV: The Mathematics of Love

The Engineer was away on a business trip, and Kitten and I were in the mood to veg out on YouTube, so I hunted for some golden oldies. We used to watch Square One TV faithfully, back when my eldest was in first grade. I can’t believe they haven’t released this show on DVD!

We found recordings of my two favorite songs (“Nine, Nine, Nine” and “8% of My Love”), but the picture quality was horrible. This video was the runner-up:

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# Elementary Arithmetic

My car makes a loud, scary, grinding noise, and of course the repair shop is closed until Tuesday — so instead of visiting relatives for the holiday weekend, I get a quiet “writer’s retreat” at home.

If you’re stuck at home, too, perhaps you’ll enjoy this bit of fun…

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# Days of Christmas with Vi Hart

If you haven’t subscribed to Vi Hart’s blog yet, what are you waiting for?

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# New Math Joke

A topologist walks into a cafe:
“Can I have a doughnut of coffee, please?”

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# Mathematical Juggling

Just for fun . . .

# Valentine’s Day: Say It with Music

If you have trouble seeing the video, it’s here on YouTube. For more information about the singers (and lyrics to this and other songs), check out the Klein Four webpage.

P.S.: You may also enjoy the Valentine’s Day Fail over at Abstruse Goose.

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# Quotable: Politics

“Let’s give the governor a break,” says Williams College mathematician Edward Burger. “If nothing else, he’s encouraging math education.”

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# Chocolate Solves Anything

[Photo by miss karen.]

Need to pass that math test? Better stock up on chocolate. According to a recent study:

Mental arithmetic became easier after volunteers had been given large amounts of compounds found in chocolate… They were also less likely to feel tired or mentally drained…

[Hat tip: Joanne Jacobs.]

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# Real-Life Story Problem

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# Key Lime Pi

This may be my favoritest ever Pi Day T-shirt, designed by the admin over at 10-Minute Math. I admit it’s not very mathy, but I’ve always enjoyed word play, and I love key lime.

The design won a Reflection T-shirt Company contest and is now available to pre-order for only \$8.99 (plus shipping). [Company seems to have gone out of business? Can’t find their website…]

Unfortunately, it won’t be available in time for this Friday’s class.

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# 500 (?) and Counting

Photo by rileyroxx.

Could this be my 500th post? That doesn’t seem possible, even counting all those half-finished-and-then-deleted drafts. Well, at least it is my 500th something, according to the WordPress.com dashboard. And surely a 500th anything is worth a small celebration, right?

## Maybe my students aren’t so bad, after all…

It has been awhile since I posted a link to Rudbeckia Hirta’s Learning Curves blog. Here are a few of her students’ recent bloopers:

# That’s Mathematics

Things are still hectic, but at least the phone company guy found the problem and got our “extended DSL” service working. “Extended DSL” is what you get when you live out in the boonies. No guarantees that it will be faster than the ancient modem, but at least it doesn’t tie up the phone line anymore.

And it is a bit faster, so I finally get to enjoy You Tube. If the video doesn’t display properly, you can find it at this link:

Funny Math Problems

# Rewriting the History of Math

Here are a couple of quick links to math in the news:

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# A Very Short History of Mathematics

This paper was read to the Adams Society (St. John’s College Mathematical Society) at their 25th anniversary dinner, Michaelmas Term, 1948. [Warning: Do not attempt to read this while drinking coffee or other spittable beverage!]

Hat tip: I found this through the math carnival at a mispelt bog.

Update: The original page has disappeared from the internet, or at least I cannot find it any more, but the Internet Archive Wayback Machine came to the rescue. After my plea for help, James Clare pointed me to the article’s new home.

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# Math Jokes

Blame it on MathNotations and his Corny Math Jokes (which actually included one I hadn’t heard before) — or maybe I have been reading too many of Chickenfoot’s strange tales — but anyway, I’m in a mood for humor.

So here are a couple of old favorites:

Hat tip: These had gotten lost in the dustbunnies of my memory until I saw the Frivolous Theorem mentioned recently at Art of Problem Solving.

Edited to add: Scott at Grey Matters recently updated his Mathematical Humor post, which may be where I had originally read these. He links to several more great MathWorld jokes, including the ever-tasty Pizza Theorem.

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# Spring Cleaning My Blog Links

Our whole family is coming down with something again. What a nuisance!

Since I don’t feel up to real cleaning, I guess it’s time to spruce up my sidebar. If you haven’t posted since November or December of last year, you’re outta there. And for those of you who use Blogger — well, I’m sorry, but if I get a persistent “Blogger: 404 – Page Not Found” then you’re gone, too. If you are still actively blogging, please send me an email.

# Secret Message

My algebra students could stand to hear this, too:

(2)(-4x2)n is not equal to (-8 )nx2n.

AAAAAARRRRGGGHH!!!!

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