Tag Archives: enrichment math

Poop Calculus

A National University of Singapore’s brochure cover promoting math and art.

A fortnight ago, Center of Math (@centerofmath) tweeted the following picture:

Imagine if Donald Trump were your high school math teacher. How would he disruptively or irreverently use the above illustration to teach some “pop (or poop) calculus” to his math-anxious Liberal Arts students?

From Epstein to Trump

President Trump’s “fun buddy” of yesteryear, Jeffrey Epstein, was unverifiably a pretty good math teacher before he became a successful financier, whose sinful soul had since journeyed to that hot fiery place, on the other side of eternity, sooner than later.

And not too long ago the president who claimed to have a “genius IQ” boasted that his “favorite” daughter is very good at numbers, which indirectly implies that she must have inherited his (or his first wife’s) “mathematical gene.”

An e-card promoting the disruptive title, “If Trump Were Your Math Teacher” (2020).
A phrase that had made its way into Urban Dictionary, but had since mysteriously disappeared from cyberspace.
Trump’s Calculus

Based on the defined meanings of f(x), what could f′′′(x) represent?

The distance between two peeing men is inversely proportional to the degree of friendship between them. (Photo © Anonymous)

or

If F′(x) = f(x), then F(x) might depict the dear speciality coffee beans eaten and excreted by civets.

The sought-after civet cat poo that meets the wants of filthy-rich coffee drinkers.

And what if G′′(x) = f(x)? Would G(x) represent the following picture?

Not all coffee beans are created equal.
Calculus for Civet Cats (and Their Humans)
Can we expect “Calculus for Civet Cats” in a-not-too-distant future?
The Calculus of Donald Trump

Let me end with two “urban calculus definitions” I coined in the aftermath of President Trump’s irrational behaviors.

Did President Trump and gang order this definition to be taken off the Urban Dictionary?
Another approved definition whose days were numbered.

Differentially and integrally yours

© Yan Kow Cheong, September 30, 2019

Life of Pi and Pi of Life

For the majority of us who aren’t born or blessed with a mathematical or symbol-minded brain, but nevertheless appreciate the austere beauty of mathematics, writing about mathematics and math education is the second best thing we’d do to console ourselves that we needn’t be first-rate mathematicians to enjoy the language of science and technology, or to appreciate the science of patterns.

Some mathematicians write novels under a pseudonym to avoid any suspicion from their faculty bosses; others compose limericks and haikus as a creative outlet to showcase their hidden poetic talents. And for the rest of us who are neither novelists nor poets, maybe submitting some definitions to Urban Dictionary, by coining new mathematical words, or redefining old ones, could be the first step to activating that atrophied right part of our brain, which is allegedly responsible for creativity.

On this Pi Day, let me share with fellow math educators eleven approved definitions related to the irrational and transcendental pi. Don’t ask me how many times I got rejected and needed to resubmit some of these definitions again, before the Urban Dictionary editors decided to approve them.

Pre-Pi Day

Pre-Pi Day seems to have been serially downvoted and subsequently deleted to prevent digital abuse, because the approved entry can no longer be accessed.

Be Rejection Proof

Rejection isn’t failure. We keep refining or redefining any rejected definitions until the editors have zero excuses to reject the resubmitted entries. I wished I’d share some recipe for these approved pi definitions, but any attempt to offer some tips to increase a math educator’s chances of getting these math words or terms approved would probably be futile, to say the least.

Over time, although I’ve managed to reduce the odds of rejection, however, some submissions inevitably end up in the little red book of the mean editors—maybe these word doctors had a bad day, or simply because I was submitting some “mathematical crap” that caused me to receive emails like the following:

Urban Dictionary – Pi-rated was not published

Thanks for your definition of Pi-rated!

A few volunteer editors read your definition and decided to not publish it. Don’t take it personally!

Pi-rated
The term to describe any faux facts about the irrational number pi.

On Pi Day, our teacher tricked us with some pi-rated math:
pi is a rational number (22/7);
pi has a different value on the moon that on earth;
pi has a value of three in the Bible.

It’s never too late to be mathematically playful, by playing your part in submitting some irreverent mathematical definitions to enliven your math lessons.

A blessed Pi Day to everyone.

© Yan Kow Cheong, March 14, 2019.

Durian Math

In Singapore, the durian is officially the only tropical fruit that is banned inside a public train or bus—to critics, it smells worse than urine combined with a pair of used socks.

Presently, transport officials are likely to confiscate the notorious fruit should someone be found conspicuously with it, until recurring public complaints force politicians to implement a fine for those caught carrying one in forbidden places.

If anyone in Singapore can be fined for failing to flush a public toilet, it’s not far-fetched to expect a penalty in a-not-too-distant future for those who inconsiderately propagate the pungent aroma of durians among Singaporeans.

A proof that Singapore is a “fine” city.

Dubbed the “King of fruits” by locals, enjoying the durian is arguably an acquired taste; however, it may cause premature death when eaten together with some types of food or drinks—check this out with your doctor to avoid going to the other side of eternity sooner than later.

For math educators who can’t stand the pungent smell of durian, much less taste it, how can they creatively make use of this much-loved or much-disliked fruit in their mathematics teaching?

Below is a definition of Durian Math I submitted to Urban Dictionary half a year ago.

Christmaths Guesstimation

In the aftermath of a church in Sarawak, Malaysia erecting a Christmas durian tree, the following estimation questions crossed my mind:

1. Guesstimate the number of durians that were used to make the Christmas tree depicted below.

A durian Christmas tree at a church in Sarawak, Malaysia. Source: @nobisha by norizan sharif on 25/12/18

2. Estimate how much the durian business in Malaysia meant for the China market is worth every year.

3. Estimate how many durians a ten-hectare durian plantation could produce every year.

4. What percentage of the Asian population love to eat the pungent-smelly durian?

Singapore Math and Durian

Below are two irreverent tweets I posted to poke fun at the notoriety of the durian among fruit lovers, who are often tickled by durianians who wouldn’t think twice about forking out more than fifty bucks for one über-smelly durian.

Modeling with Durian

1. Math Trail à la Durian

Make a short trip to Malaysia or Thailand during the peak durian season. Try to get hold of a dozen-odd types of durian from the local market or some durian plantations owners. Compare their prices, weights, textures, pH levels, smells, or tastes; and make some conjectures based on nasal, oral, and tactile factors. Does the number of spikes of some durian type exhibit Fibonacci-like behaviors?

2. Death by Durian

Model how many “durian bombs” pseudo-jihadists planning a terrorist hoax in some public places like a college campus or shopping mall would need to simulate some panic or irrational fear among the undergraduates or shoppers.

What are the odds that one of Singapore’s neighboring frenemies could one day use the durian as a low-tech weaponry to neutralize her, just as man-made haze pollution from unfriendly neighbors could potentially be weaponized to suffocate an entire nation?

3. A “Fine” Durian

Imagine that you have been assigned to draft a set of rules that would penalize those caught with durians in forbidden public areas in Singapore. Model a “fines guideline” that wouldn’t unfairly punish those who selfishly insist on polluting their milieux with the nose-unfriendly smell of durians.

New Year, New Entries

On a more positive or non-apocalyptic note, for this new year, some of you might wish to redefine Durian Math or add a new twist to it, as you discover new ways to infuse the term in your math lessons.

A blessed New Year 2019 to all math educators around the world.

Esplanade Theatre—Singapore’s “The Durian.” Photo source: visitsingapore.com

Bibliography & References

Church in Malaysia creates durian Christmas tree http://bit.ly/2CyThI0

Chinese funds fuelling boom in Malaysia’s durian plantations http://bit.ly/2Lz9pMj

Rotten durian causes Melbourne university evacuation http://www.bbc.co.uk/news/world-australia-43940122

Singapore scientists reveal origins of durian’s pungent aroma http://www.bbc.co.uk/news/world-asia-41563300

© Yan Kow Cheong, January 2019.

Pi Day in Singapore

Thousands of students around the world celebrate Pi Day today, but local math students in Singapore can only dream of being part of this annual mathematical event. Singapore math students, teachers, and parents don’t (and can’t) celebrate Pi Day, as long as they officially follow the British style of writing their dates (DD/MM/YY).

What makes matters worse is that this year, Pi Day falls on the first day of the one-week school break, which makes it almost impossible for hardcore math teachers, who want to buck the calendrical trend, to get their students excited about the properties and beauties of the number Pi.

Until Singapore switches to the American style of writing dates (MM/DD/YY), which may not happen, at least during my lifetime, however, this shouldn’t prevent us from evangelizing the gospel of Pi among the local student population.

Here are seven e-gifts of the holy Pi, which I started musing about 314 minutes ago on this Pi Day.

Pi Day vs. Abacus Day

  

A 14-Month Year for Singapore ONLY!

  

Where Are You in Pi?

  

Heavenly Pi

  

The Numerology (or Pseudoscience) of Pi

  

In Remembrace of the Late Singapore PM 

  

Biblical Pi vs. Mathematical Pi

   

Happy Pi Day!

© Yan Kow Cheong, March 14, 2016.

The 12 Problems of CHRISTmaths

Vintage Christmas—Just like Baby Jesus two millennia ago! Vintage Christmas—Just like Baby Jesus two millennia ago!

Christmas is a golden and joyful opportunity for number enthusiasts and math geeks to sharpen their creative mathematical problem-solving skills.

Here are 12 CHRISTmaths cookies that may help you shake your brain a little bit in the midst of Christmas festivities.

Warning: Refrain from forwarding this post to relatives or friends living in countries, which are intolerant of Christmas and Christianity, such as Brunei, Saudi Arabia, and Somalia, as it’s haram for “infidels” to take part in any kind of Christmas celebrations. And I assume that includes reading any on-line materials deemed un-Islamic or un-Mohammedan, which might lead believers astray from the faith.

1. Unlucky Turkeys

Estimate the number of turkeys that make their way to the supermarkets every year.

2. A Xmas Candy

Mary wanted to buy a candy that costs 25 cents. A dated vending machine would take one-cent, five-cent, and ten-cent coins in any combination. How many different ways can she use the coins to pay for the candy?

Christmastize your code!Remember to scan your Christmas item!

3. The Dimensions of a  Cross

A square of side 25 cm has four of its corners cut off to form a cross. What is the perimeter of the cross?

4. The Number of Crossings

Two lines can cross one time, three lines three times, four lines six times, and five lines ten times. If there are 25 lines, what would be the maximum number of crossings be?

5. An Eco-Xmas

If all instances of the word “CHRISTMAS” were replaced with “XMAS,” how much ink and paper (or Xmas trees) could you save every year? How much money could be channelled back to feeding the poor and the hungry during the festive season?

XMaths Tech© T. Gauld’s You’re all just jealous of my jetpack (2013)

6. Number of Xmas Cards

In an age of Xmas e-cards and video cards, how many Christmas greetings cards are still being sent worldwide? How many trees are being saved every festive season?

7. Does Xmas! have 25 digits?

1! = 1, 2! = 1 × 2 = 2, 5! = 1 × 2 × 3 × 4 × 5 = 120—a 3-digit number, and 10! = 1 × 2 ×⋯× 10 = 3,628,800—a 7-digit number.

(a) Without a calculator, how would you verify whether the number 25! has precisely 25 digits or not.

(b) Which positive integers n (other than the trivial case n = 1) for which n! has exactly n digits?

GST with no thanks to Father XmasGST (or VAT) with no thanks to Father Xmas

8. Xmas Trees

Guesstimate how big a forest would 25 million Christmas trees occupy.

9. Folding papers

Fold a single piece of paper perfectly in half, from left to right. How many creases will there be after the 25th fold, when you continue folding so that all the rectangles are folded into two halves each time?

10. Pre-Xmas Tax

Imagine Singapore were to implement a pre-Christmas tax on all kinds of Christmas marketing before the first week of December. Estimate how many extra million dollars would the Income Tax department collect every festive season.

Folding a Santa Claus© Anonymous Folding a Santa Claus

11. A Xmas Quickie or Toughie

What is the sum of the last two digits of 1! + 2! + 3! +⋯+ 24! + 25!?

12. An Ever-Early Xmas

Show that as one celebrates more and more Christmases (or, as one gets older and wiser), Christmas seems to come earlier every year.

Xmas Möbius Strips Christmas Möbius Strips

References

Gould T. (2013). You’re all just jealous of my jetpack. New York: Drawn & Quarterly.

Yan, K.C. (2011). Christmaths: A creative problem solving math book. Singapore: MathPlus Publishing.

Zettwoch, D., Huizenga, J., May, T. & Weaver, R. (2013). Amazing facts… & beyond! with Leon Beyond. Minneapolis: Uncivilized Books.

A Xmas Bonus: 25 CHRISTmaths Toughies from Singapore ?? http://tinyurl.com/q9w3ne9

 

Selected Hints & Answers

2. 12 ways. Hint: Make an organized list.

3. 100 cm. 

4. 300 crossings.

5. About 30 million gallons of ink, 500 square miles of paper, and $15 trillion could be saved.

6. Hint.

7. (b) n = 22, 23, 24.

9. 225 – 1.

11. 4.

12. Hint: Why as one gets older, time appears to fly faster.

2012-12-21 23.13.28

© Yan Kow Cheong, December 25, 2015.

 

Anything Funny about Singapore Math?

Math educators, especially stressed [often self-inflicted] local teachers in Singapore, are always on the look-out for something funny or humorous to spice up their oft-boring math lessons. At least, this is the general feeling I get when I meet up with fellow teachers, who seem to be short of fertile resources; however, most are dead serious to do whatever it takes to make their teaching lessons fun and memorable.

20140421-203849.jpg
© Sidney Harris Sea animals are mathematical, too!

It’s often said that local Singapore math teachers are the world’s most hardworking (and arguably the world’s “most qualified” as well)—apparently, they teach the most number of hours, as compared with their peers in other countries—but for the majority of them, their drill-and-kill lessons are boring like a piece of wood. It’s as if the part of their brain responsible for creativity and fun had long been atrophied. A large number of them look like their enthusiasm for the subject have extinguished decades ago, and teaching math until their last paycheck seems like a decent job to paying the mortgages and to pampering themselves with one or two dear overseas trips every other year with their loved ones.

Indeed, Singapore math has never been known to be interesting, fun, or creative, at least this is the canned perception of thousands of local math teachers and tutors—they just want to over-prepare their students to be exam-smart and to score well. The task of educating their students to love or appreciate the beauty and power of the subject is often relegated to outsiders (enrichment and olympiad math trainers), who supposedly have more time to enrich their students with their extra-mathematical activities.

Singapore Math via Humor

20140421-203921.jpg
© Sidney Harris The lost art of Roman numerals

A prisoner of war in World War II, Sidney Harris is one of the few artists who seems to have got a good grasp of math and science. While school math may not be funny, math needn’t be serious for the rest of us, who may not tell the difference between mathematical writing and mathematics writing, or between ratio and proportion. Let Sidney Harris show you why a lot of things about serious math are dead funny. Mathematicians tend to take themselves very seriously, which is itself a funny thing, but S. Harris shows us through his cartoons how these symbol-minded men and women are a funny awful lot.

Angel: “I’m beginning to understand eternity, but infinity is still beyond me.”

20140421-203941.jpg© Sidney Harris There is nothing new under the mathematical sun!
20140421-204019.jpg
© Sidney Harris Isn’t mathematics just a man-made game?
20140421-204119.jpg© Sidney Harris The world’s first “mathematical plagiarizer”
20140421-204146.jpg© Sidney Harris The aftermath of Pi addiction
20140421-204413.jpg© Sidney Harris Maybe we’d soon spot some bunnies running around!
20140421-204454.jpg© Sidney Harris Some step just needs to be accepted on faith!
20140421-204714.jpg© Sidney Harris Who says mathematicians don’t need drugs?

Mathematical humor is a serious (and dangerous) business, which few want to invest their time in, because it often requires an indecent number of man- or woman-hours to put their grey matter to work in order to produce something even half-decently original or creative. The choice is yours: mediocrity or creativity?

Humorously and irreverently yours

References
Adams, D. S. (2014). Lab math. New York: Cold Spring Harbor Laboratory Press.
Harris, S. (1970). What’s so funny about science? Los Altos, Ca.: Wm. Kaufmann, Inc.

© Yan Kow Cheong, August 20, 2015.

Check out an inexpensive (but risky) way to make a Singapore math lesson less boring: The Use of Humor in Mathematics. The author would be glad to visit local schools and tuition centers to conduct in-service three-hour math courses for fellow primary and secondary math teachers, who long to bring some humor to their everyday mathematical classrooms—as part of their annual 100 hours professional upgrading. Please use his e-mail coordinates on the Contact page.

Some Advice for Singapore Mathletes

20140205-183957.jpg

Here are some pointers I would share with my students at the start of a secondary math olympiad programme. In Singapore, most mathletes attending these enrichment classes are usually selected by the form or math teacher, who tends to choose the best three math students from each class to form a small group of 15 to 20 participants. They would then graduate to represent the school after attending a six-, eight-, or ten-session training programme, depending on the mathematical needs and wants of the school.

• Take your time! Very few contestants can solve all given problems within the time limit. For instance, in the Singapore Mathematics Olympiad (SMO), both at the junior and senior levels, [unconfirmed] feedback based on different schools’ results hints to the fact that those who can win a medal hover around five percent.

Interestingly but disturbingly, an SMO mathlete who can get six or seven out of 35 questions correct may still win a bronze medal, revealing how unmoderated olympiad math papers had been in recent years, going by the abnormally high rate of failures among the participants. This is primarily due to the fact that few, if any, faculty members who set these competition papers, are familiar with what elementary and middle school teachers are covering in local schools.

• Try the “easier” questions first. The questions aren’t set in ascending order of difficulty. It’s not uncommon to see easier questions in the second half of the paper.

• Olympiad questions don’t “crack” immediately. Be patient. Try various approaches. Experiment with simple cases. Working backwards from the desired result in some cases is helpful.

• If you’re using a contests book, and you’re stuck, glance at the “Hints” section. Sometimes a problem requires an unusual idea or technique.

• Even if you can solve a problem, read the hints and solutions. The hints may contain some ideas or insights that didn’t occur in your solution, and they may discuss intuitive, strategic, or tactical approaches that can be used elsewhere.

Remember that modeled or elegant solutions often conceal the torturous or tedious process of investigation, false starts, inspiration and attention to detail that led to them. Be aware of the behind-the-scenes hours-long dirty mathematical work! When you read the modeled solutions, try to reconstruct the thinking that went into them. Ask yourself, “What were the key ideas?” “How can I apply these ideas further?”

• Go back to the original problem later, and see if you can solve it in a different way, or in a different context. When all else fails, remember the reliable old friend, the guess-and-check strategy (or heuristic, as it’s being arguably called in Singapore)—for instance, substituting the optional answers-numbers given in an MCQ into some given equation or expression may yield the answer sooner than later.

Meaningful or creative problem solving takes practice, with insightful or elegant solutions not being the norm. Don’t get discouraged if you don’t seem to make any headway at first. The key isn’t to give up; come back to the question after a day or a week. Stickability and perseverance are two long-time buddies for full-time problem solvers.

Happy problem solving!

20140205-184012.jpg

© Yan Kow Cheong, Feb. 7, 2014.

Mathematical Fiction Is Not Optional

Picture

“The Parrot’s Theorem” (translated from “Le Théorème du Perroquet”) was an instant bestseller in France when it was published in 1998.

Sylvia Nasar’s A Beautiful Mind and G. H. Hardy’s A Mathematician Apology are two nonfiction mathematical classics for both mathematicians and mathematics educators. Lesser known are the mathematical novels which often feature characters whose speciality is number theory, also known as higher arithmetic, and elevated as math’s purest abstract branch.

Mathematics à la Tom Clancy

Two novels that revolve around famous unsolved problems in mathematics are Philibert Schogt’s The Wild Numbers and Apostolis Doxiadis’s Uncle Petros & Goldbach’s Conjecture.

If you’re looking for math, women, sex, and back-stabbing, The Wild Numbers is a math melodrama unlikely to disappoint.

Picture

Winner of the New South Wales Premier’s Prize

 

Fictional math

Who are these mathematical fiction books targeted? Math and science teachers? Educated laypersons? Pure mathematicians may like to read them, yet at the same time they may complain that the mathematics discussed in these books is anything but rigorous.

These books seldom fail to convey the following subtle messages:

• The thin line between mathematical genius and madness.

• The search for mathematical truth at all costs, and the heavy price of finding it.

• The arrogance and pride of pure mathematicians who look down on their peers, most of whom work as applied mathematicians and research scientists.

• The relatively high divorce rate among first-rate mathematicians as compared to their peers in other disciplines.

• Mathematics is apparently a young’s man game; one has past one’s prime if one hasn’t written one’s best paper by the age of 40.

• Mathematicians are from Mars; math educators are from Venus.

• Pure mathematicians (or number theorists) are first-rate mathematicians; applied mathematicians are second- or third-rate mathematicians. To the left of the “mathematical intelligence” bell curve are math educators from schools of education, and high-school math teachers.

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“Reality Conditions” is collection of 16 short stories, which is ideal for leisure reading—it’s suitable for promoting quantitative literacy, or it’d serve as the basis for a creative course on “Mathematics in Fiction.”

The joy of reading mathematics

Let’s rekindle the joy of appreciating mathematics for mathematics’s sake. Let’s welcome poetry, design thinking, and creativity, whatever ingredient that may help to draw the community into recognizing and appreciating the language of science and of technology. These “pure-math-for-poets” titles have a place in our mathematics curriculum, as they could help promote the humanistic element of mathematics.

Here are ten titles you may wish to introduce to your students, as part of a mathematics appreciation or enrichment course.

The New York Times Book of Mathematics

The Best Writing on Mathematics 2010 

Clifton Fadiman’s Fantasia Mathematica

Clifton Fadiman’s The Mathematical Magpie

Don DeLillo’s Ratner’s Star

Edwin A. Abbott’s Flatland

Hiroshi Yuki’s Math Girls

John Green’s An Abundance of Katherines

Philip J. Davis’s The Thread: A Mathematical Yarn

Thomas Pynchon’s Gravity’s Rainbow

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Juvenile fiction—A child prodigy and his friend tried to create a mathematical formula to explain his love relationships.

References

Green, J. (2006). An abundance of Katherines. New York: Dutton Books.

Guedj, D. (2000). The parrot’s theorem. London: Orion Books Ltd.

Kolata, G. & Hoffman, P. (eds.) (2013). The New York Times book of mathematics: More than 100 years of writing by the numbers. New York: Sterling.

Hiroshi, Y. (2011). Math girls. Austin, Texas: Bento Books.

Pitici, M. (ed.) (2011). The best writing on mathematics 2010. Princeton, New Jersey: Princeton University Press.

Wallace, D. F. (2012). Both flesh and not: Essays. New York: Little, Brown and Company.

Woolfe, S. (1996). Leaning towards infinity: A novel. NSW, Australia: Random House Australia Pty Ltd.

© Yan Kow Cheong, September 12, 2013.

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Murderous math that doesn’t kill!