Tag Archives: problem solving

The Joy of Swiftematics

March 3, 2024Humor, Mathematical Humor, Problem Solving, Recreational Math, Singapore Math, Theomaticsbusiness, conspiracy, demonology, devil, entertainment, ERAS Tour, godlessness, grant, idol worship, idolatry, MAGA, music, New Age, pop star, problem posing, problem solving, Satan, Singapore, Singapore Tourism Board, sorcery, Swiftematics, Swiftonomics, Taylor Swift, theomatics, Trumpism, US politics, witchcraftKow-Cheong Yan

Last July, millions across Asia competed for just 300,000 tickets to see Taylor Swift in the “fine” city of Singapore, which will host the only stop in Southeast Asia for the singer’s Eras Tour. Organizers said 22-plus million people registered for pre-sale tickets while online registrations passed the one million mark.

And last night, even pop singer Swift, who kicked off her six sold-out shows at the 55,000-seat National Stadium, couldn’t avoid creating some light-hearted political rift or jealousy among some ASEAN members.

*Time* magazine’s Person of the Year in 2023

Last month, after Thai Prime Minister Srettha Thavisin “complained” that Singapore had brokered a deal to “pay the pop star up to US$3 million for each of her six concerts—in exchange for keeping the shows exclusive to Singapore in Southeast Asia,” the Singapore Tourism Board admitted it “supported the event through a grant,” sans revealing its size or any conditions attached to it. Guesstimate the amount of grant that was given to stage these coveted events.

Even one unhappy politician from the Philippines said “this isn’t what good neighbors do” and called for his country to register its opposition with Singapore’s embassy. Go ahead, Mr. Joey Salceda.

Cartoon by Shannon Wheeler. #NewYorkerCartoons

Political instability, radical ideology that threatens violence to Western values, and poor infrastructure are oft-unspoken key factors for concert promoters to convince the pop superstar to give regional hubs like Bangkok, Manila, Kuala Lumpur, and Jakarta a miss as part of her “Eras Tour.”

Math in Pop Culture

With so much excitement (and concern from conservative or puritan parents) about Swift’s six-show tour in Singapore, how could math educators seize the opportunity to excite otherwise mathematically indifferent or apathetic students with some Swift-related math questions or activities?

For instance, what about coining some math or dismal science terms like Swiftematics and Swiftonomics to promote some creative problem posing?

A Singapore Math Definition of *Swiftematics*

Could the Boyfriend Make It on Time?

Posing real-life Swift-related math questions is only limited by our imagination. Below is a nontrivial question that was posted on Facebook, whose solution is anything but straightforward.

Posted by Judy Smith Hallett on “Maths Jokes Daily”

Swift’s Carbon Footprint

In 2022, Swift topped the list of celebrities with the highest private jet CO₂ emissions. If her jet pollution were about x times more than the average person’s total annual emissions, estimate x.

The next item is a Swift- or math-friendly question posted by news anchor Peter Busch.

The Numerology of Taylor Swift

Last month, after reading about Swift’s serial infatuation with her “lucky” number 13, I made an attempt to define Swiftie Math, which is based on the numerology (or pseudoscience) of Taylor Swift.

Since I’ve yet to receive any approval or rejection of the term—whether the editors see it fit for publication—I’d skip posting it online for now.

The Swift-Biden Conspiracy

Theomatically, MAGA evangelicals (or MAGA Xtians, where X ≠ Christ)—a subset of Christian nationalists—in red-pilled states haven’t failed to warn netizens about the “satanic” influences of Taylor Swift’s songs, but have hypocritically or selectively remained silent about the fraudulent, criminal, and sexual activities of their “political savior.”

Does Taylor Swift CAST SPELLS On Her Listeners?!

Conspiracies about the singer’s alleged support for President Biden have been rife in political and religious circles to paint Ms. Swift as an “ambassador of Satan,” who’s shown zero sign in supporting Trump and his cult.

Puritan Trumpublicans are hell-bent to warn millions of Swifties from unknowingly becoming witches lest they and their idol lose their souls, but, interestingly, hardly anything from these patriots calling for a nationwide corporate prayer for the soul of their beloved un-Christian ex-president.

Musically & mathematically yours

References

Taylor Swift named Time’s ‘Person of the Year’ https://www.cnn.com/2023/12/06/media/taylor-swift-time-person-of-the-year?cid=ios_app

‘Cruel Summer’ for Taylor Swift fans in Asia as Singapore shows sell out https://www.cnn.com/2023/07/14/business/taylor-swift-tour-singapore-asia-popularity-intl-hnk-dst

Taylor Swift’s journey from country icon to pop superstar https://www.cnn.com/2022/10/21/entertainment/gallery/taylor-swift/index.html

Does Taylor Swift CAST SPELLS On Her Listeners?! https://youtu.be/SDmzNDrj2NI?si=-gWMOb7CwsswytYV

The Clock Problem

August 13, 2023Humor, Mathematical Humor, Problem Solving, Recreational Math, Singapore Mathanalog clock, analog time, art, clock, digital clock, digital time, faux problems, ill-posed question, olympiad math, out-of-the-box thinking, problem posing, problem solving, timeKow-Cheong Yan

On July 12, @PicturesFoIder x-ed (or tweeted) the following picture:

Is this another ill-posed math question? Or just another arguably creative solution that put the teacher or tutor in a catch-22 response?

Let’s look at a sample of comments for and against the given answer.

They don’t want a digital clock!
This is the correct answer for anyone that is somehow confused! 🤔

Teacher needed to say clock with hour and minute hands.

The question says “small clock”, not “analog clock”, therefore the answer is correct.

This is everything what’s wrong with current educational system.
It sure does prepare you.
To think in the frameworks they want you to think. For example “there is only one right solution to a problem and that ain’t it”

thats what happens when you let kids use ipads at a young age

This student should be transferred to art school immediately

On one hand I’m scared that the new generation can’t read physical clocks, on the other hand, I’m surprised by the out of the box thinking

If my child received a X for that answer, I would challenge it. There is nothing at all wrong. It is a small clock showing ten past eleven. 100% accurate. IF they wanted a conventional clock face that should have been stated. I’d have given 2 ticks for innovative thinking!

The question doesn’t specify that it meant “analog clock” plus it says “10 minutes past 11:00” which implies digital time as opposed to “10 minutes past 11 o’clock” which would imply analog time.

I would have drawn an analog and digital clock with a note saying the request was ambiguous and next time be more specific. Also how small? Another ambiguous request

How many of these responses would you agree or disagree with? Valid or invalid, or preposterous in some instances, most of these comments can’t be discounted offhand.

Followers or Oddballs?

At a time when politicians, pastors, or even prisoners are often hypocritically or insincerely pushing for an overhaul of their rigid educational system (from which they themselves benefited much)—which promotes rote learning or regurgitation, or prepares students to the test—are math teachers ready for students’ unconventional or disruptive solutions, which often border on the ridiculous or irreverent?

If a child (or a trained chimpanzee) presented the solution below to the above problem, what would your response or reaction be?

Would you mark it wrong or partially correct, because he or she had failed to take account that time on a clock is determined by the hour hand alone, with the minute hand acting as a mere convenience? Or in layman terms, the hour hand had also moved when the minute hand took a sixty-degree turn.

Or would you take this opportunity to introduce nonroutine (or more subtle faux) questions like the ones below?

1. What is the angle measure between the hands of a clock at 10 minutes past 11:00?

2. A clock reads ten minutes past eleven. What time would the clock read if the hands of the clock were interchanged?

3. Are there other times of the day when the hands of a clock would also show the same angle measure as when they were at 11:10?

The Positives of Ill-Posed Questions

An ill-posed question, or the unexpected answers to such a flawed question, is a gold mine for creative mathematical problem posing. It not only provides an off-the-wall sense of humor, but also gives math educators an opportunity to address students’ mathematical loopholes or their half-baked understanding of concepts.

Positively & creatively yours

The Pseudo-Proportional Problem

May 29, 2023Problem Solving, Recreational Math, Singapore Mathcreative thinking, creativity, critical thinking, elementary school math, grades 1–6 math, lateral thinking, primary school math, problem solving, proportion, pseudo-proportional, rate, ratio, woke mathKow-Cheong Yan

On May 23, 2023, @OrwellNGoode tweeted the rate question below, with the “teacher” marking the student’s answer of 20 minutes wrong, and showing why it’d be 15 minutes instead.

Who the heck takes 10 minutes to saw a board?

I’ve no idea what grade level this math question was being assigned to. Although questions on ratios and rates are formally introduced in grades 5–6 in most parts of the world, however, it’s not uncommon to spot these types of mathematical quickies in grades 1–4 Singapore math olympiad papers to trap the unwary.

Assuming that the word problem didn’t come from a bot or from ChatGPT, the teacher’s intuitive reasoning may be said to be ratio-nally sound but rationally incorrect in solving this pseudo-proportional math question.

Logically or mathematically speaking, few math teachers would disagree that the student was right and the teacher was wrong.

This arguably “badly worded” or “ill-posed” math question provides a fertile ground for a number of possible (valid or creative?) answers, probably much to the annoyance of most math teachers and editors, who often feel uncomfortable or jittery about questions with more than one possible answer.

Indeed, there is no shortage of supporters to defend a “15 minutes” answer. For example, since there is zero mention that the length of each board is of equal length (and we can’t assume it to be so), or as each sawing might take place in a different direction, the “logical” answer of 20 minutes can’t be taken as mathematical gospel truth.

That three pieces need two cuts or sawings is unanimous among problem solvers. The bone of contention is the assumed length of the second cut. Say, if the second cut was half as long as the first one, then it’d take half the time of the first cut, in which case the answer of 15 minutes would be practically plausible.

It looks like we’re only limited by our imagination or creativity to rationalize why the answer can’t in practice be 15 minutes or any other duration, by using a different (creative) reasoning from the flawed one provided by the “teacher.”

Like most artificial or impractical word problems in school math, this rate question debatably falls short of design thinking and is thus open to different interpretations or assumptions, which might also weaponize some “anti-woke” math educators to ban or censor these types of “confusing or tricky” math questions.

Ironically, this is why injecting a dose of realism or creativity to these oft-ill-posed or contrived math questions would help open up the minds of uncritical or unquestioning math educators.

Don’t just answer the questions, question the questions.

Right Answer, Wrong Method

May 11, 2023Problem Solving, Singapore Matharithmetic, commutative law, concept, grade 3 math, method, method of solution, methodology, multiplication, pedagogy, primary 3 maths, problem solving, process, product, Singapore, Singapore mathKow-Cheong Yan

A grade 3 question with right answer marked wrong.

A grade 3 Singapore math question made some waves among netizens in yesterday’s local paper. https://bit.ly/3VOzpHP

Debatably, the root of the discussion centers around the “right” way to do multiplication.

Process v. Product

In Singapore, it’s not uncommon for elementary school teachers and tutors to witness a student’s incorrect method of solution to a word problem that produces the correct answer. This frustrating situation arises far too often than what many of them would want to admit.

Due to a shortage of time, most school teachers pay lip service to the method of solution, pretending not to see that the students’ workings fall short of what is expected of them. These time-starved civil servants would simply look at the children’s answers and conveniently mark them “correct.”

In some cases or circles, it’d not be surprising too that some teachers or tutors themselves are oblivious of the correct method or procedure to solve a (routine or nonroutine) math question.

Personally, I’d want to give these school teachers the benefit of the doubt that they’re merely “lazy” rather than because they’re conceptually blind to the mathematical stain on their students’ worksheets.

Getting students to master a math concept with understanding requires time and effort (and also patience and pain), and most stressed teachers can’t afford either one in the name of having to “rush to complete the syllabus.”

For example, students’ or parents’ parroting that “multiplication is repeated addition” gives teachers and tutors quasi-zero clues whether they’ve understood the multiplication concept or not.

With regard to this grade three routine question that made the headlines, writing the correct procedure, without the teacher explaining to the student why he or she went wrong, only solves half the problem.

Understandably, some parents would argue that teachers shouldn’t be too rigid or radical about their children’s half-baked solutions to avoid dampening their self-esteem. For mathematically puritan math educators, the process is more important than the product.

Procedural proficiency with little understanding of math concepts would only produce elementary school drill-and-kill math graduates—the whys are as important as the hows.

An early penalty is better than a later one when it comes to a child’s learning of basic mathematical concepts in their formative years, which must be accompanied by a teacher’s or tutor’s explanation of the incorrect solution.

And in this grade three routine multiplication question, order matters.

Math Word of the Day: Mathemachicken

June 28, 2022Humor, Mathematical Humor, Problem Solving, Recreational Math, Singapore Mathban, chicken, egg, humor, inflation, kampong chicken, Malaysia, math, mathophobia, organic chicken, philosophy, problem solving, profiteering, Singapore, Ukraine, warKow-Cheong Yan

I can’t recall what prompted me to coin “mathemachicken” three-odd years ago. Was it the aftermath of setting or solving an unhealthy number of word problems on chickens or eggs, or both?

Not too long ago, in Organic Chicken Rice for the Rich, I hatched up a meme and offered some math questions on organic and kampong chickens. https://bit.ly/3y1fXvL

Early this month, the world read about Malaysia’s decision to ban the export of chickens (but not eggs) to its frenemy neighbor Singapore. In fact, even before the ban, the prices of chicken eggs were already skyrocketing in supermarkets, which sounds more like a case of synchronized profiteering strategies among exporters, distributors, and supermarkets than anything else, but after some Opposition members had denounced the unjustified inflated prices, things have since stabilized more or less.

Ukrainian Eggs 4 Singapore

During Singapore’s “circuit breaker”—a PC term for “lockdown”—we’re blessed with white eggs flown from Ukraine. I recall that some supermarkets had promotions like “Buy One, Get One Free” or “Buy Two, Get One Free” to lure locals to try Ukrainian eggs. Since the war, the import of these bigger and cheaper eggs seems to have come to a halt.

Probably no animal is more popular than the chicken in math word problems—even the beloved bunny comes a distant second. Be it the use of their heads, eyes, legs, or eggs, the chicken remains the animal of choice among mathematical problem posers.

Tens of thousands of brain-friendly and unfriendly math questions on chickens and eggs around the world make their way into canned and creative math textbooks every year, which makes millions of math-anxious students worldwide to “chicken out” to avoid being given all kinds of labels by peers and parents for their oft-irrational fear or failure to solving them.

Philosophically Speaking

If you were a chicken, would you feel privileged or pissed off by the way your name is being used, abused, or misused in school textbooks and workbooks?

Do you think it’s long overdue that you and your feathery friends and foes sue the publishers and the Ministries of Education around the world for showing disrespect or even disdain towards the chicken community?

On a lighter note, if it looks like a chicken and clucks and counts like a chicken, you never know: it might be a mathemachicken.

Which came first: The chicken or the egg?

Math Word of the Day: Pithon

June 25, 2022Humor, Mathematical Humor, Problem Solving, Recreational Math, Singapore Mathadder, Florida, humor, math, parody, pie, pizza, problem solving, python, serpent, Singapore, snake, viperKow-Cheong Yan

The day before, we read that a female Burmese python weighting 98 kg and nearly 5 m was caught in Florida. She’s the largest snake ever found in that state before her death, pregnant with an amazing 122 eggs; if stretched vertically, she’d be as tall as a giraffe.

In Florida, where now lives the Viper in Chief after being ousted from the White House, who’s since preoccupied himself with terrorizing those who refuse to propagate his lasagna of lies, pythons have become pests due to irresponsible pet owners of yesteryears releasing or allowing pet pythons to escape in the wild.

With no major predators, Florida’s subtropical climate has provided serpents and snakes a conducive breeding ground for them to multiply, often outcompeting native species. Who knows? Alien vipers might eventually outnumber local pythons, if left on their own to populate the land.

Recently, some human vipers mounted a “mathematical insurrection” against textbook publishers for allegedly promoting “woke math” to K–12 students. And a rising number of foreign pythons are set to keep Florida’s annual “Python Challenge” alive—this year, the event runs from August 5–14 and is expected to lure around 500+ python hunters from 25 different states.

🐍🔢: Math with Pythons & Pithons

Like math questions on vampires and zombies, those on pythons (and pithons) are no less frightening or exciting to problem solvers. Below are two examples:

It is estimated that the female Burmese python, which was caught after Floridian researchers used a male “scout” to find her, was up to 20 years old. In human years, would she be as old as the Viper in Chief?

Python Pies or Pizzas: In 2021, the winner of the “Python Challenge” captured 223 pythons, while the longest snake was 15 feet long. Imagine if this year’s captured foreign pythons were ethically killed and exotically used to make pies or pizzas, how many pieces of either one could be made by the chefs at Mar-a-Lago for the “Florida Python Food Festival”?

Math Word of the Day: Bitcoin

June 16, 2022Humor, Mathematical Humor, Problem Solving, Recreational Math, Singapore MathBitcoin, Blockchain, Cryptocurrency, Ether, math, mining, problem posing, problem solving, recreational math, Satoshi Nakamoto, Singapore, Singapore mathKow-Cheong Yan

The advent of cryptocurrencies like Bitcoin and Ether has provided math educators worldwide with fertile resources to indulge themselves in creative mathematical posing and solving.

Unfortunately, the negative perception that cryptocurrency or crypto is a vector for serious organized crime and money laundering has led millions of half-informed or risk-averse folks to adopt a wait-and-see attitude vis-à-vis Bitcoin transactions.

Who/What Is Satoshi Nakamoto?

Nobody knows the identity of Satoshi Nakamoto. If the name isn’t a he or she or it, could the name be a covert group of cryptographers and mathematicians?

Like the modern-day equivalent of the Bourbaki group—the collective pseudonym of a group of predominantly French mathematicians in the 1930s, who tried to axiomatize mathematics to make it more rigorous?

So far, the few suspects—digital-currency addict Nick Szabo, Japanese mathematician Shinichi Mochizuki, and Co.—all have denied being the founder of Bitcoin, except for Australian computer scientist who loudly but unprovenly claimed that he is Nakamoto.

Crypto Math

Posing fertile crypto math questions is only limited by our imagination. Thanks to Bitcoin or cryptocurrency, NFTs, and the Metaverse, I’ve toyed around with a number of crypto math questions.

Below are a sample of Bitcoin-related questions that I hope would make their way into a math booklet fit for publication in a-not-too-distant future.

Bitcoins are divided into Satoshis: one hundred million Satoshis in each Bitcoin. At the current Bitcoin price, what fraction of a U.S. cent is worth the smallest fraction of a Bitcoin?
In 2010, a pizza restaurant agreed to accept ten thousand Bitcoins in exchange for two large pizzas. At today’s exchange rate, how much would each pizza be worth?
In September 2021, El Salvador approved Bitcoin as a secondary currency; in April 2022, Central African Republic followed suit. Which rogue or war-torn nation in Asia or the Middle East would be the first one to make Bitcoin its official currency? Or would it be “fine” city Singapore that would lead the way in becoming SE Asia’s crypto hub?

Crypto Apocalypse: What are the odds that due to hyperinflation (or a possible WW3 in the aftermath of the senseless Ukraine-Russia war) people would start losing faith in Bitcoin to the point that it suffered the same fate as the Zimbabwean dollar bills?
A golf resort is rumored to have been gifted with 13.257 ETH and 12.5 bitcoin from a Middle Eastern prince. How much did the shady resort receive in cash donation from their criminal donor?

Crypto Winter Is Coming!

With news of a crypto winter in the horizon, let’s hope that the mathematics of Bitcoin or cryptocurrency wouldn’t deter math educators globally from getting involved in creative mathematical thinking and problem solving.

I don’t know about you, but I’m waiting for Bitcoin to drop under $10,000 as my next buy alert. The future lies in Bitcoin—or in blockchain.

Richly yours

Continue reading →

Otter Math

December 16, 2021Singapore Mathchurch, competition, condominium, education, family planning, fertility, fish, humor, koi fish, low-tech warfare, mammal, math, nuisance, otter, parody, population, problem solving, recreational math, sea lion, seal, Singapore, Singapore math, SPCA, swimming pool, trauma, urban spaces, warfare, wildlifeKow-Cheong Yan

In the aftermath of a Singapore permanent resident who was bitten 26 times by a romp of otters in 10 seconds at the Singapore Botanic Gardens, which attracted mixed reactions from both locals and foreigners, I entertained the idea how math teachers could use this once-in-a-lifetime incident to indulge in some problem posing for elementary math students.

As natural swimmers, Singapore’s smooth coated otters, once thought to be extinct, have made a comeback to the island-state. They are believed to have swum across the Straits of Johore and made their homes here. Their present “locations of choice” are: Bishan Park, the Kallang River estuary, Marina Bay, and Singapore Botanic Gardens—and the Singapore Zoo.

Singaponacci Numbers and the C-Word

Mathematically or theoretically speaking, without culling, Singapore’s otters could exponentially grow as fast as Fibonacci’s rabbits, although otter sexperts think there are alternative humane ways of family planning.

An “otterman” who was furious that netizens had uttered the C-word against the cute-looking furry creature blamed them for spreading white lies or fake news about these “critically endangered animals.”

The Fear Factor

These “urban pests” seem to be better protected under the Wildlife Act than we humans against the Delta and Omicron variants. They’ve the SPCA behind them, but we’ve the POFMA* and FICA** over us to police our online behaviors.

Can you distinguish an adult otter from a baby seal?

Co-Existing with Covid and Otters

Last week, in the light of Singapore’s otter saga making the headlines overseas, I tweeted the following:

Otter Math: If the present population of 150 otters doubles every leap year, while Singapore’s annual fertility rate continues to head south, with zero immigration allowed, when would otter babies outnumber human babies? https://lnkd.in/gVfqjEZ8

Animals’ cruelty against humans: Otters bit a Singapore Botanic Gardens visitor 26 times in 10 seconds. What are the chances that such a similar incident happening again are less than the odds of someone being abducted by an alien? https://bit.ly/3oH93IO

Canals, Condos & Churches

Singaporean river otters are notorious in devouring dear ornamental fish found in condominiums and churches. If the probability of rich people disliking otters is x folds higher than that of poor folks, guesstimate x.

What are the odds that someone from a middle-income family in Singapore is more likely to cross paths with an otter family thanks to a greening Singapore, which provides an ideal milieu for otters to breed stresslessly, compared to Singaporeans, who often can’t even find a little space to do their private business?

Otter: Singapore’s Unofficial Mascot

Think of Singapore as an otter, and its frenemies-neighbors as crocodiles and monitor lizards. When threatened by its natural resources-rich, but militarily weaker, neighbors, Singapore would hit back to defend itself. Sure, they’d use low-cost warfare tactics like forest haze and arsenic-polluted rainwater to frustrate their little-red-dot neighbor—a form of asymmetric warfare to neutralize the enemy by natural and man-made means.

How not to mismanage Singapore’s otter population

Thou Shalt Not Catch an Otter! Fine: S$X

How much is the fine for someone caught capturing or trapping otters in the “fine” city of Singapore? What are the odds that a repeated offender could get jailed or/and caned for their illegal activity?

What If? Exotic Singapore Cuisine

Does otter meat taste more like chicken, beef, or pork? What if Singapore started farming otters to satisfy the desire of adventurous gourmets? Like crocodile, deer, or frog meat, could the legalized consumption of otter meat be a lucrative food business for both locals and aliens, who are looking for an exotic dish (halal, kosher & vegetarian), if there were a mismanaged otter population control in future?

An Otters Naming Contest

In the past, Singapore had the famous or notorious romp of otters called the “The Marina 10.” Now, we’ve local groups like the Zouk Family. Has the raft of otters that bit the über-unlucky British man 26 times at the Singapore Botanic Gardens been christened? If not, why about having a national contest to name them following the recent biting incident, which could have potentially led to Singapore’s first case of “death by otters”?

Otter Math for Mature Students

Let’s end with a grades 1–2 otter math question to tickle actress Sandra Bullock’s two children and their peers, who’ve been jabbed (or maybe even boosted) with a dose or two of the Singapore math vaccine to protect them against the plague of innumeracy:

After seeing an otter family of twelve devouring the fish in their condominium pond, a number of children were traumatized for weeks. Five children had recurring nightmares about the attack. There were three fewer children having nightmares than those needing counseling.

a) If two boys and a pair of twin sisters met up with a school counselor, how many children were altogether affected by the otter invasion?

b) Guesstimate how many fish were eaten up by the hungry otters in a few minutes before they made their way to the swimming pool.

Answer: (a) 13 children (b) Hint: Think about the demographics of the condo residents.

Answer: 1. 8 koi fish. Can you solve the question in more than one way without algebra?

* POFMA: Protection from Online Falsehoods and Manipulation Act ** FICA: Foreign Interference (Countermeasures) Act

Durian Math

January 2, 2019Singapore MathChristmas, Christmas durian tree, CHRISTmaths, creativity, Durian, durian math, enrichment math, Esplanade Theatre, estimation, fines, guesstimation, humor, modeling, problem solving, recreational math, Singapore math, terrorismKow-Cheong Yan

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

The Fake Bar Model Method

November 1, 2017Bar Modeling, Problem Solving, Singapore Math, Singapore Model Methodalgebra, bar method, Bar Model Method, Bar Modeling, grade 6 math, mathematics writing, Primary 6 Maths Quesrion, problem solving, PSLE Maths, Stack method, stack model method, stack modelingKow-Cheong Yan

Recently, I was peeping at some postings on the Facebook PSLE Parents group, and I came across the following question:

Philip had 6 times as many stickers as Rick. After Philip had given 75 stickers to Rick, he had thrice as many stickers as Rick. How many stickers did they have altogether?

Here are two solutions that caught my attention to the above primary or grade 6 word problem.

Pseudo-Bar Model Method?

Arguably, the solution by the first problem solver offered to parents looks algebraic, to say the least. Some of you may point out that the first part uses the “unitary method,” but it’s the second part that uses algebra. Fair, I can accept this argument.

Since formal algebra, in particular the solving of algebraic equations, isn’t taught in primary or grade six, did the contributor “mistake” his solution for some form of bar model solution, although no diagram was provided? It’s not uncommon to see a number of pseudo-bar model solutions on social media or on the Websites of tuition centers, when in fact, they are algebraic, with or without any model drawings.

Many parents, secondary school teachers, or tutors, who aren’t versed with the bar model method, subconsciously use the algebraic method, with a bar model, which on closer look, reveals that the mental processes are indeed algebraic. No doubt this would create confusion in the young minds, who haven’t been exposed to formal algebra.

Does the Second Solution Pay Lip Service to Design Thinking?

What do you make of the second solution? Did you get it on first reading? Do you think an average grade five or six student would understand the logic behind the model drawing? From a pedagogical standpoint, the second solution is anything but algebraic. Although it makes use of the bar model method, I wonder what proportion of parents and their children could grasp the workings, without some frustration or struggle.

One common valid complaint by both parents and teachers is that in most assessment (or supplementary) math books that promote bar modeling, even with worked-out solutions to these oft-brain-unfriendly word problems, they’re often clueless how the problem solver knew in the first place that the bar model ought to be presented in a certain way—it’s almost as if the author knew the answer, then worked backwards to construct the model.

Indeed, as math educators, in particular, math writers, we haven’t done a good job in this area in trying to make explicit the mental processes involved in constructing the model drawings. Failure to make sense of the bar models has created more anxiety and fear in the minds of many otherwise above-average math students and their oft-kiasu parents.

Poor Presentation Isn’t an Option

Like in advanced mathematics, the poor excuse is that we shouldn’t be doing math like we’re writing essays! No one is asking the problem solver or math writer to write essays or long-winded explanations. We’re only asking them to make their logic clear: a good presentation forces them to make their thinking clearer to others, and that would help them to avoid ambiguity. Pedantry and ambiguity, no; clarity and simplicity, yes!

Clear Writing Is Clear Thinking

It’s hard work to write well, or to present one’s solution unambiguously. But that’s no excuse that we can afford to be a poor writer, and not a good thinker. As math educators or contributors, we’ve an obligation to our readers to make our presentation as clear as possible. It’s not enough to present a half-baked solution, on the basis that the emphasis in solving a math problem is to get the correct answer, and not waste the time to write grammatically correct sentences or explanations.

I Am Not a Textbook Math Author, Why Bother to Be Precise?

As teachers, we dread about grading students’ ill-written solutions, because most of us don’t want to give them a zero for an incorrect answer. However, if we’re convinced based on their argument that they do know what they’re doing, or show mathematical understanding or maturity of the concepts being tested, then we’d only minus a few marks for careless computation.

Poorly constructed or ill-presented arguments, mathematical or otherwise, don’t make us look professional. Articulating the thinking processes of our logical arguments helps us to develop our intellectual maturity; and last but not least, it makes us become a better thinker—and a better writer, too.

Yan's One Minute Math Blog

News & Views about Singapore Math