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?
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.
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.
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?
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.
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
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?
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?
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?
(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 (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.
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.
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.
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.”
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.
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.
In the aftermath of the death of Singapore’s founding father, Mr. Lee Kuan Yew (1923–2015), a number of numerological tidbits (or numerical curiosities, to put it mildly) floated on social media, which got a number of apparently self-professed innumerates pretty excited. Here are three such postings that I saw in my Facebook feed and on WhatsApp.
The WhatsApp message gives the impression that it was the works of some “pseudo-mathematician,” but it could very well have been the digital footprints of a “mathematical crank” or an amateur-numerologist, who wanted to tickle mathophobics with such numerical coincidences.
Did Singapore’s numerologists (or pseudo-mathematicians) fail to point out some of the following numerological absurdities?
The digital root of Mr. Lee’s birth year is 1 + 9 + 2 + 3 = 15, which stands for the last two digits of the year he experienced his last heartbeat.
The pollution index for that week was in an unhealthy range, and the average PSI for the six-day mourning period was about 91.
Or, were there exactly 91 priests on vigil at an undisclosed Roman Catholic Church, who were interceding for Mr. Lee to ensure that his heavenly destination is 100% secured, although his manifold deeds to the nation inarguably exceeds the number of his political faux pas, especially vis-à-vis his political enemies or opponents?
Or, did 91 senior monks and nuns (or did I mistake them for disciples of Shintoism?) resort to “synchronized chanting” to ensure that the highest level of enlightenment be bestowed on the late Mr. Lee, who might be reincarnated as a future Buddha for his numerous selfish deeds towards his oft-ungrateful and unappreciative fellow citizens?
And did any police personnel verify whether there were 91,000 odd mourners in black attire on that Black Sunday, not to say, 91 VIPs or Heads of States who attended the eulogy, depending on one’s definition of a VIP?
The Numerology of the Old Guard
One Facebook numerological factoid that circulated in the first post-LKY week was the following:
Singapore’s political fathers who outlived the biblical three-scores-and-ten lifespan
At face value, these nonagenarians had their blessed lives prolonged up to “four scores and ten and one” years. Sounds like their good earthly or political deeds were good karma for their longetivity? Are they the recipients of the following success equation?
Sacrifice + Service + Incorruptibility + Risk = Political Success + Longevity
Observe that simply taking the difference between the birth year and the death year of Mr. S Rajaratnam suggests that he died at the age of 91; however, if we look closely at the month dates (Feb. 25, 1915 – Feb. 22, 2006), he was still 90 years old, when he passed away. The same argument goes for Dr. Toh Chin Chye (Dec. 10, 1921 – Feb. 3, 2012), who wasn’t yet 91, when he died. So, always take the pseudoscience of numerology with a grain of salt. As with fengshui charlatans, a degree of skepticism towards numerologists of all sizes and shapes isn’t an option—wear your critical-thinking cap when meeting, or reading about, these paranormal folks!
To rational non-punters or non-gamblers, betting on someone’s death date, whether he or she was poor or rich on this side of eternity, seems like an extreme case of bad taste, or simply showing zero respect for the deceased and their family members. However, in superstitious circles, that practice isn’t uncommon among mathematically challenged or superstitious punters, who think that bad luck paranormally translates into good omen, if they bet on the digits derived from the death date or age of a recently deceased person.
In fact, during the nation’s six-day mourning period for its founder, besides the long queues of those who wanted to pay their last respects to Mr. Lee at the Parliament House, another common sight islandwide were meters-long lines of 4D or TOTO punters, who wanted to cash in on the “lucky digits” to retire prematurely, hoping to lay hold of the traditional 5Cs (cash, car, condo, credit card, country club), coveted by hundreds of thousands of materialistic Singaporeans.
Instead of promoting a numerological or pseudoscientific gospel based on Mr. Kuan Yew’s death date or age, which only helps to propagate superstition and pseudoscience, perhaps a “mathematically healthy” exercise would be to leverage on the D-day to teach our students and their parents some basic numerical properties—for example, conducting a recreational math session on “Number Theory 101” for secondary 1–4 (or grades 7–10) students might prove more meaningful or fruitful than dabbling in some numerological prestidigitation, or unhealthy divination.
A Search for Patterns
91 is the product of two primes: 91 = 7 × 13
91 = 1² + 2² + 3² + 4² + 5² + 6²
91 is also the sum of three squares: 1² + 3² + 9²
Are there other ways of writing the number 91 as a sum of squares?
91 = 33 + 43
Non-Numerological Questions to Promote Problem-Solving Skills
Let’s look at an “inauspicious number” of elementary- and middle-school (primary 5–secondary 4) math questions, which could help promote numeracy rather than numerology among students and teachers.
1. Sum of Integers
Show that the number 91 may be represented as the sum of consecutive whole numbers. In how many ways can this be done?
2. The Recurring Decimal
What fraction represents the recurring decimal 0.919191…?
3. Palindromic in Base n
For what base(s) will the decimal number 91 be a palindromic number (a number that reads the same when its digits are reversed)? For example, 91 = 101013.
4. The Billion Heartbeat
Does a 91-year-lifespan last less or more than a billion heartbeats?
5. Day of the Week
Mr. Lee Kuan Yew (September 16, 1923–March 23, 2015) died on a Monday. Using the 28-year cycle of the Gregorian calendar, which day of the week was he born?
6. One Equation, Two Variables
If x and y are integers, how many solutions does the equation x² – y² = 91 have?
7. Singapore’s New Orchid
A new orchid—Singapore’s national flower—had been named after Mr. Lee: Aranda Lee Kuan Yew. Using the code A = x, B = x + 1, C = x + 2, …, , does there exist an integer x such that ARANDA sums up to 91? In other words, does there exist a numerological system such that A + R + A + N + D + A = 91?
8. Singapore’s Coin Goes Octal
The alleged involvement of Mr. Lee in Singapore’s “lucky” octagonal one-dollar coin
There is an apocryphal story that had circulated for many years linking Mr. Lee Kuan Yew with Singapore’s octagonal one-dollar coin. A high-ranking monk had apparently told Mr. Lee that Singapore’s fortune would continue to rise only if Singaporeans were to carry a bagua—the eight-sided fengshui symbol. That prediction allegedly prompted the Monetary Authority of Singapore to issue the octagonal shape of the nation’s one-dollar coin.
That rumor was later put to rest by no other than self-declared agnostic Mr. Lee himself in one of his books, Hard Truths. He remarked that he had zero faith in horoscopes, much less the pseudoscience of fengshui.
What is the sum of the interior angles of the Singapore’s eight-sided coin?
9. Show that the largest number k for which the decimal expansion of 2k does not contain the digit 1 is 91.
1. One example is 91 = 1 + 2 + 3 +⋯+ 13. 2. 91/99. 5. Mr. Lee was born on a Sunday. 6. Hint: Show that x² – y² = 91 has 8 integer solutions. 9.Hint: Use a computer to verify the result.
Most of us may not admit it, but we’ve all fallen victim to the lure of innumeracy—the mathematical equivalent of illiteracy—consciously or unconsciously. Here are twenty of my favorite innumerate events I often witness among my numerate and semi-numerate friends, colleagues, and relatives.
• Taking a 45-minute train journey to save a few dollars at Carrefour or Walmart.
• Lining up for hours (or even days, if you’re in China?) to buy an iPhone or iPad.
• Paying a numerologist or geomancy crank to divine your “lucky” and “unlucky” days.
What is the smallest and the largest four-digit number?
• Visiting a feng-shui master to offer advice how best to arrange your furniture at home, or in your office, to ward off negative or “unwanted energies.”
• Buying similar items in bulk at discounted prices, which you don’t need but because they’re cheap.
• Offering foods to idols [aka gods and goddesses] in the hope that they’ll bring you good luck and prosperity in return.
• Offering gifts to hungry [angry?] ghosts to appease them lest they come back to harm you and your loved ones.
• Buying insurance policies against alien abduction, meteorites, biological warfare, or the enslavement of the apocalyptic Beast.
• Filling up lucky draw vouchers, by providing your personal particulars for future pests-marketeers and time-sharing consultants.
The Hello Kitty Syndrome in Singapore—Purchase of no more than four sets per customer will start past midnight!
• Betting on horses, football, stocks, and the like—any get-rich activities that may cut short a 30-year working life, slaving for your mean or half-ethical bosses 9-to-6 every day.
• Buying lottery tickets to short-circuiting hard work, or to retiring prematurely.
• Going on annual pilgrimages to seeking blessing from some deities, prophets, saints, or animal spirits.
• Outsourcing your thinking to self-help gurus or motivational coaches.
• Going for prices that end in 99 cents, or acquiring auctioned items that are priced at $88 or $888—the number 8 is deemed auspicious among superstitious Chinese.
An NIE motto to innumerate undergrads: “Always give more than 100%!”
• Replying to spam mails from conmen and “widows” from Nigeria, Russia, or China, who are exceedingly generous to transfer half of their inherited money to your bank account.
• Taking a half-day leave from work, or faking sickness to visit the doctor, to line up for hours to buy McDonald Hello Kitties.
• Lining up overnight to buy the latest model of a game console, or to secure an apartment unit of a newly built condominium.
• Enrolling for courses that cost over a thousand bucks to learn “Effective Study Habits of Highly Successful Students.”
• Postponing all important meetings, or avoiding air traveling, on a Friday the thirteenth.
• Canceling all major business dealings, weddings, or product launches during the Ghost (or Seventh) Month.
Now is your turn to share with the mathematical brethren at least half a dozen of your pet innumerate activities—those numerical idiocies or idiosyncrasies— that you (or your loved ones) were indulged in at some not-too-distant point in the past.
In my formative years, I don’t recall any elementary school teachers sharing some mathematical puns with us. I suppose that the arithmetic of yesteryear was often taught in the most uninteresting way by many who probably didn’t look forward to teaching it to a bunch of noisy kids.
Recently, while reading Stewart Francis’s Pun direction: Over 500 of his greatest gags…and four crap ones!, I came across a number of numerical puns that might even be appreciated by some nerdy seven-year-olds. Stewart Francis is considered to be the best Canadian comedian from Southern Ontario. Here are two dozen odd math-related puns I’ve stolen from his punny book. Hope you enjoy them!
The number of twins being born has doubled.
They also stole my calculator,
which doesn’t add up.
Four out of ten people are used in surveys. Six are not.
Crime in lifts is on the rise.
“QED Gravestone Small Poster” www.cafepress.com
I recently overcame my fear of calculators.
It was a twelve-step program.
Women are attracted to foreign men. I’ve heard that at least uno, dos, tres times.
All seventeen of my doctors say I have an addictive personality.
There’s a slim chance my sister’s anorexic.
Truthfully, we met at a chess match, where she made the first move.
Is my wife dissatisfied with my body? A tiny part of me says yes.
I read that ten out of two people are dyslexic.
From: wherethepunis.com
They now have a website for stutterers, it’s wwwdotwwwdotwwwdotwwwdotdotdot.
I have mixed race parents, my father prefers the 100 metres.
I’m the youngest of three, my parents are both older.
Clichés are a dime a dozen.
I’m an underachiever 24-6.
I used to recycle calendars. Those were the days.
www.cafepress.com
I’ve learned two things in life. The second, is to never cut corners.
‘Any man who lives his life in accordance to a book is a fool.’ Luke 317
I can say ‘No one likes a show off’ in forty-three languages.
I was once late because of
high-fiving a centipede.
Of the twenty-seven students in my maths class,
I was the only one who failed.
What are the odds of that, one
in a million?
I’ve met some cynical people in my twenty-eight years.
I was good at history.
Wait a minute, no, no I wasn’t.
I was terrible at school. I failed maths so many times, I can’t even count.
A rectangular enclosure is 30 meters wide and 50 meters long. Calculate its area in square meters.
Solution
The My Pals Are Here Math Series
The My Pals Are Here series has been rumored to have been edited and ghostwritten by a hundred odd editors and freelancers in the last decade.
Lack of mathematical rigor was initially targeted against Dr. Fong Ho Kheong and his two co-authors by American profs in the first or/and second editions —probably by those who were “ghost advisors or consultants” for Everyday Math.
Deconstructing the Singapore Model Method
1. It’s a problem-solving strategy—a subset of the “Draw a diagram” strategy.
2. It’s a hybrid of China’s line method and Russia’s box (or US’s bar) method.
3. It’s the “Draw a diagram” strategy, which has attained a brand status in mathematics education circles.
4. It’s a problem-solving method that isn’t recommended for visually challenged or impaired learners.
5. It allows questions traditionally set at higher grades (using algebra) to be posed at lower grades (using bars).
Painless Singapore Math
Perhaps that’s how we’d promote Singapore math to an often-mathophobic audience!
A Singapore Ex-Minister’s Math Book
Dr. Yeo had the handwriting below depicted in his recreational math book, regarding his two granddaughters, Rebecca and Kathryn.
Stealing the idea from Nancy Vu’s “Just Little Things,” I tried to reflect on some mathematical things that give us delight and pleasure as we go about our hectic 24/7/365 lives.
Here are some of my personal mathematical pleasures.
It’s now your turn to reflect on some aha! mathematical moments to share with the rest of us.
References
Wu, N. (2013). Just little things: A celebration of life’s simple pleasures. New York: A Perigee Book.
© Sidney Harris There is nothing new under the mathematical sun! 
