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Singapore Math

Friday, March 10, 2023

Math à la Japonaise

We need to thank Mrs. Marie Kondo for advocating that tidying up needn’t be obeyed as an eleventh commandment, especially for a significant number of us who can’t afford to live sans a mess, or who just refuse to be Konned by her enviable minimalist lifestyle.

Since the tidying consultant has been in the limelight recently after her long overdue admission that the art of tidying up could be an optional activity for those who can’t stand the sight of all kinds of oft-dated, sentimental, or hoarded items lying around the house (and in the office), I thought it’s apt to share about “KonMari Math,” which I christened two years ago, to show that even math educators too haven’t been spared by the gospel or philosophy of the organizing goddess.

Math word du jour

Photo from math prof @mathematicsprof on 17/2/19

Personally, I’m dazzled by most things Japanese: origami, sushi, wasabi, not to say, soroban (Japanese abacus—square-rooting, cube-rooting, differentiating, and integrating), Kumon math, Sakamoto math, Sangaku, and Wasan.

After being introduced to Mr. Kenji Wakabayashi by my ex-colleague and friend, Mr. O.K. Heng, to learn about the ABCs of the Sakamoto Maths Method, I was later offered the opportunity to attend a months-long series of math talks on the Japanese problem-solving heuristic (or “problem-solving strategy” as it’s known in some parts of the globe).

To certify that I’d mastered Sakamoto math, I reluctantly had to take an exam with fellow participants who’re much younger than me. I was already around forty then, and needless to say, by then, it’d been a while since I last sat for a math proficiency test or exam.

Front cover of the manual

Today, I’m thankful to Mr. Wakabayashi who gave me an opportunity to get a strong foundation on Sakamoto math, which has proved to be a more advantageous or intuitive problem-solving strategy than the bar model method in a number of problem situations.

What is even more amazing is that I attended all these Japanese math lessons without forking out a penny. Talking about being blessed mathematically (and financially), when other participants or franchise sponsored trainers have to pay hundreds of dollars to attend these twice weekly and weekend classes.

Indeed, Sakamoto math offers paid, sponsored, or guest attendees another method of solution to solving brain-unfriendly word problems. I think a Singapore math educator-turned-trainer ought to be versed with not only the bar model method, but also with the stack model method and the Sakamoto math method—a trinity of problem-solving strategies.

Recently, while working on a bar modeling manuscript, I accidentally came across some Wasan (or Japanese math) materials, which further solidifies my knowhow of Nippon math, especially some of the techniques I learned in Sakamoto math moons ago.

May I encourage all of you to expose yourself to the richness of Wasan, which would help broaden and deepen your appreciation and knowledge of multicultural math, if you’re open to learning different problem-solving strategies (or heuristics) commonly used in countries with a rich mathematical heritage.

Of course, to learn Sakamoto math effectively, do it preferably under a master-trainer from Japan—never mind their accent—rather than merely reading the notes of your child or nephew who’s signed up for a Sakamoto math course.

May the learning of Nippon math and multicultural math (Vedic math, bar model method, stack model method, line model method, …) spark mathematical joy in your life.

Wishing you many blessed joy-sparking or aha! moments.

Mathematically & multiculturally yours


Kondo, M. (2022). Marie Kondo’s Kurashi at home. New York: Ten Speed Press.

Yan, K.C. (2016). Sangaku — Japanese temple geometry. Geometrical quickies & trickies. Singapore: MathPlus Publishing.

© Yan Kow Cheong, March 10, 2023.

A New Yorker cartoon by Evan Lian.

Wednesday, February 8, 2023

Freedom from Crypto Addiction

Cure from crypto addiction needn’t be costly!

Help is now dearly available for those who’re hard hit by the recent crypto winter.

For those who can’t afford the nouveau-riche treatment, or who’re thinking of following Anthony Bourdain’s or Jeffrey Epstein’s template, because there seems to be no way out, know that there’s a (better) way to come out of that hell.

A better and faster (or cheaper) solution for crypto addicts would be to attend a counseling-and-praying session or two so that they’d be delivered once for all from the spirit of gambling.

Complete deliverance and healing is a mere prayer away if they’d turn to the Deliverer-and-Healer who has the power to free them from their short- or long-term addiction or affliction or persecution.

The Miracle Worker who turned water into wine, or who used five loaves of bread and two fish to feed five thousand people or families, is waiting and willing to deliver them from their gambling or years-long bad habit or addiction if only they agree or humble themselves to be delivered.

May their pride (or unbelief or negative faith or ignorance) not be a stumbling block to their being freed from crypto addiction, massive debt, or financial ruin.

Freely yours

© Yan Kow Cheong, February 8, 2023.

Friday, January 27, 2023

Crime Watch and Crime Math

Singapore is known for its low crime rate in the developed world, and those who occasionally peek at what’s happening in the island-state might be surprised to read about more local and foreign shoplifters being recently caught in CCTV-equipped supermarkets and shopping centers islandwide.

Dark Data

Below is an immoral statistics question that could serve as a “teaching moment” to warn both elementary and middle school (or upper primary and lower secondary) students against shoplifting and crime, especially when inflation around the world is at an all-time high.

The 2020–2022 estimated losses from the thefts of milk powder at retailers in Singapore are as follows:

2020: $18,000 (73 cases)

2021: $26,000 (96 cases)

2022: $27,000 (80 cases)

2023: $XY,000 (Z cases)

Based on past crime statistics, and in the light of a gloomy global economy that could bring about a financial apocalypse if the war in Ukraine dragged on, and should Mother Nature lose her patience with earthlings in spite of frequent natural calamities visiting the planet in recent years, predict the number of milk powder thefts and the accompanying monetary loss that would occur in the “fine” city of Singapore, in 2023.

How much revenue (or fines) could the authorities generate from these shoplifters-turned-resellers of milk powder (contaminated or not) in the coming decade?

Would there be a (higher) jail sentence for repeated offenders of infant formula? Or is caning in the pipeline for hardcore thieves? Or hundreds of community service hours for those unfit to be behind bars for whatever health or wealth reasons?

A Moral/Social Issue 

How many of these shoplifters genuinely couldn’t afford to feed their kids, especially when there is quasi-zero government assistance for the unemployed or underemployed, or for senior citizens with zero pension or savings in their “golden” years?

Do the shoplifters (and potential rioters) belong to some demographic groups that need the authorities to step in to avoid social disorders like public strikes and hate crimes perpetrated by racists-supremacists-turned-opportunists, which we’re witnessing in some right-wing political circles or red-pilled states?

From Profit to Profiteering

Like pharmaceutical companies that are notoriously known to overprice or overcharge their products, milk powder manufacturers don’t seem to be any morally different from them. Unless their dear milk powder came from holy cows or goats that have been anointed by Vatican-approved priests!

A Formula for an Equitable World

The social and political chaos plaguing many parts of the globe provides math educators worldwide an opportunity to step up and speak out against rogue politics and profiteering, poverty and inequality, and crime and robbery.

Some degree of equality or equity could come to pass via creative mathematical problem solving and active moral mindfulness on the part of math educators to help right some of the social ills, political hypocrisies, and business malpractices.

Remember: Low crime doesn’t mean no crime.

© Yan Kow Cheong, January 27, 2023.