Somashis Gupta, our editor, shares the rich educational heritage of Bengal and discusses about Subhankar Das , a 14th-century mathematician renowned for his innovative rhyming method of solving complex problems. Discover how his unique system, known as ‘Shubhankari,’ transformed mathematical education long before the advent of modern technology.

It is often touted that Bengal’s golden age of education bloomed during the Renaissance era. Yet, this view overlooks the deep-rooted educational heritage that predated this period. The seeds of education in Bengal were sown long before the Renaissance, tracing back to the Pala dynasty around 700 CE. According to some historians, the first patshalas (primary schools) were established by King Dharma Pala in Bengal in 778 CE. Over time, these institutions flourished, laying a foundation for the rich educational tradition Bengal would come to be known for.

The 14th century, a period marked by significant historical and cultural development, saw the rise of a remarkable mathematician whose work would leave an indelible mark on the annals of history. Raja Banku Roy’s reign in Bengal witnessed the extraordinary talents of Subhankar Das, a mathematician renowned not only for his numerical prowess but also for his unique method of problem-solving through rhymes.

One sunny afternoon, King Banku Roy encountered an exceptionally tall palm tree and was intrigued by its height. Unable to find a satisfactory answer from his courtiers, the King summoned Subhankar Das, who happened to be passing by. Despite having recently resigned from his palace position due to disagreements with fellow officers, Subhankar promptly solved the problem by calculating the tree’s height based on its shadow.

What set Subhankar Das apart was his innovative approach to solving complex mathematical problems orally. He developed a system known as ‘Shubhankari,’ which involved rhyming to simplify the memorization and application of various mathematical formulas. In an era devoid of calculators and computers, Subhankar’s method provided an accessible way for students to grasp arithmetic concepts.

Renowned linguist Dr. Sukumar Sen has noted that Subhankar’s approach included using riddles and brief verses, known as “Arya” and “Torja” in Bengali, to convey intricate mathematical concepts. One of Subhankar’s most notable works is “Chhotrish Karkhana,” a comprehensive book detailing the administration during the early 18th century under the Nawabs of Bengal. This book contains over two thousand shlokas, or rhyming verses, that were memorized by students, illustrating the widespread use of his educational methods.

Here is an example of Subhankar’s ingenious rhyming problem:

“Tireesh hath brikkha ek chhilo uchcho sthane,
Churaay uthibe ek keet koray monay,
Diba bhage dosh haath uthite lagilo,
Nisha joge ashto haath neechete namilo
Na paaye jaabat chura kore say aton
Kato diney uthechhilo karo nirupon”

(There was a 30-hand high tree on elevated land, and an insect decided to reach the top. Every morning it climbed 10 hands but slid down 8 hands at night. How many days did it take for the insect to reach the top?)

In this rhyme, the insect climbs a net of 2 hands each day and would take 10 additional days to cover the remaining 20 hands, making it a total of 20 days to reach the top.

Another example demonstrates Subhankar’s problem-solving approach:

“Sarobare bikashito kamal nikar
Madhulobhe elo tatha onek bhromor,
Proti padme boshi bhromor jugol
Oliheen rahe tobey ekti komol
Ekek bhromor boshe prottek kamole
Baki rohe ek oli, sankhya deho boli”

(Lotus flowers bloomed in a pond. Bees came in numbers, with each pair of bees sitting on each lotus, but one lotus remained empty. If one bee sits on each flower, then one bee does not get a flower. How many bees and lotuses were there?)

By solving the equations derived from this problem, we find that there were three lotuses and four bees.

Subhankar Das’s mathematical rhymes were initially celebrated for their simplicity and effectiveness. However, over time, they were reduced to mere quick fixes for mathematical problems. His method, known as ‘Manash-anka’ (mental maths), enabled individuals to perform arithmetic calculations mentally, without the aid of paper or pen.

Despite his contributions, Subhankar Das’s name and his mathematical puzzles have largely faded from memory. Today, he remains a forgotten hero of Bengal’s educational history, with only a few ancient texts and a locality in Bankura bearing his name to honor his legacy.

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