The numerals you are reading right now (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) originated in India. The decimal place-value system that makes modern arithmetic possible was developed by Indian mathematicians over a period of several centuries, beginning around the fifth century CE. The concept of zero as both a number and a placeholder, without which positional notation cannot function, was formalized in India before it appeared anywhere else in the world.
These contributions alone would place India among the most important mathematical traditions in history. But the Indian mathematical legacy extends far beyond numerals. Indian scholars developed sophisticated methods in algebra, trigonometry, number theory, and infinite series, some of which anticipated results that European mathematicians would not discover for centuries. The story of Indian mathematics is one of the great intellectual achievements of human civilization, and it remains surprisingly unfamiliar to many people educated in the Western tradition.
Aryabhata and the Dawn of Indian Mathematics
The earliest major figure in the classical Indian mathematical tradition is Aryabhata (476 CE, born in what is now Bihar or Kerala). His work Aryabhatiya, written in 499 CE when he was twenty-three years old, is a concise treatise covering arithmetic, algebra, trigonometry, and astronomy in just 121 verses.
The Aryabhatiya contains several remarkable results:
- An approximation of pi as 3.1416, accurate to four decimal places and explicitly described as approximate (“approaching” the true value)
- A table of sine values (called jya) computed at intervals of 3.75 degrees, more accurate than any trigonometric table then available
- Methods for solving linear and quadratic equations
- An algorithm for computing square and cube roots
- The claim that the Earth rotates on its own axis, explaining the apparent motion of the stars (a remarkable insight, contested by later Indian astronomers but physically correct)
Aryabhata used a positional number system in his astronomical calculations, though he employed an alphabetical notation rather than the decimal digits we use today. His work established the Indian tradition of combining pure mathematics with practical astronomy, a combination that would drive mathematical innovation for the next thousand years.
Brahmagupta and the Invention of Zero
The mathematician who most clearly formalized the use of zero as a number was Brahmagupta (598-668 CE), who worked in Ujjain, in central India. His masterwork, the Brahmasphutasiddhanta (The Corrected Doctrine of Brahma, 628 CE), contains the first known rules for arithmetic with zero:
- A number plus zero equals the same number
- A number minus itself equals zero
- A number multiplied by zero equals zero
- Zero divided by zero equals zero (this last rule is incorrect by modern standards, but the attempt to define it was groundbreaking)
Brahmagupta also introduced rules for arithmetic with negative numbers, which he called “debts” (as opposed to “fortunes” for positive numbers). He stated that a debt subtracted from zero is a fortune, and a fortune subtracted from zero is a debt: in modern notation, 0 − (−a) = a and 0 − a = −a. These rules, basic to us, were revolutionary in the seventh century. Neither Greek nor Roman mathematics recognized negative numbers as legitimate quantities.
The Brahmasphutasiddhanta also contains solutions to Pell’s equation (x² − Ny² = 1), a problem in number theory that European mathematicians would not tackle until Fermat posed it in the seventeenth century. Brahmagupta found the general method of solution over a thousand years earlier.
The Decimal System Goes West
The Indian decimal place-value system, with its ten digits (including zero) and its positional notation, was transmitted to the Islamic world in the eighth and ninth centuries. The Persian mathematician al-Khwarizmi wrote a treatise on Indian numerals around 825 CE, which was later translated into Latin and became the primary source through which Europe learned the system.
The transmission was slow. European merchants and scholars initially resisted the new numerals, preferring the Roman system they were accustomed to. Fibonacci (Leonardo of Pisa) helped popularize them in Europe with his Liber Abaci (1202), which demonstrated the superiority of the Indian system for commercial arithmetic. By the sixteenth century, Indian (or “Arabic”) numerals had displaced Roman numerals for most purposes across Europe.
The impact was enormous. Without positional notation and zero, modern arithmetic, algebra, and computing are impossible. Try multiplying MCMXCIV by XLVII using Roman numerals, and the advantage of the Indian system becomes immediately obvious. The entire edifice of modern mathematics rests on a notational foundation built in India.
The Kerala School: Calculus Before Newton
The most astonishing chapter in Indian mathematics is the work of the Kerala school, a lineage of mathematicians and astronomers in southwestern India that flourished from the fourteenth to the sixteenth century. The Kerala school, founded by Madhava of Sangamagrama (c. 1340-1425), developed many of the key concepts of calculus two to three centuries before Newton and Leibniz.
Madhava discovered infinite series expansions for trigonometric functions:
- The infinite series for pi: π/4 = 1 − 1/3 + 1/5 − 1/7 + … (known in Europe as the Leibniz formula, published by Leibniz in 1676)
- The power series for sine: sin(x) = x − x³/3! + x⁵/5! − … (known in Europe as the Taylor series for sine, published by Taylor in 1715)
- The power series for cosine: cos(x) = 1 − x²/2! + x⁴/4! − …
- The power series for arctangent: arctan(x) = x − x³/3 + x⁵/5 − …
These results were recorded by Madhava’s successors, particularly Nilakantha Somayaji (1444-1544) in his Tantrasangraha and by Jyesthadeva (c. 1500-1575) in the Yuktibhasa, which provides detailed proofs (or “rationales”) for the series. The Yuktibhasa is considered the first calculus textbook in history, predating European calculus texts by over a century.
The Kerala mathematicians did not develop the general concept of a derivative or an integral in the way that Newton and Leibniz did. Their work was focused on specific applications (computing accurate values of trigonometric functions and pi) rather than on building a general theory. Whether their results influenced European mathematics through indirect transmission (via Jesuit missionaries who visited Kerala in the sixteenth century) is a subject of ongoing scholarly debate. No direct documentary evidence of transmission has been found, but the question remains open.
Ramanujan: The Genius from Kumbakonam
The most famous Indian mathematician in the modern era is Srinivasa Ramanujan (1887-1920), whose story is one of the most extraordinary in the history of mathematics. Born in Erode, Tamil Nadu, and raised in the temple town of Kumbakonam, Ramanujan was largely self-taught. He learned mathematics from a single textbook (A Synopsis of Elementary Results in Pure and Applied Mathematics by G.S. Carr, a compilation of over 5,000 theorems stated without proof) and developed an astonishing body of original results while working as a clerk in Madras.
In 1913, Ramanujan sent a letter to G.H. Hardy, a leading mathematician at Cambridge, containing over 100 mathematical statements. Hardy later described the letter as the most remarkable he had ever received. Some of the results were already known. Some were new and were later proved correct. Some were so strange that Hardy could not determine whether they were true. He invited Ramanujan to Cambridge.
Ramanujan arrived in England in 1914 and spent five years collaborating with Hardy. Their partnership produced some of the most important results in number theory and analysis of the twentieth century, including the Hardy-Ramanujan formula for the number of partitions of an integer and fundamental work on the properties of highly composite numbers.
Ramanujan’s health deteriorated in England (he suffered from what is now believed to have been hepatic amoebiasis or tuberculosis, exacerbated by the English climate and wartime food shortages). He returned to India in 1919 and died in April 1920, at the age of thirty-two. He left behind notebooks filled with thousands of unproved formulas, many of which have taken decades to verify and some of which remain unproved.
A Mathematical Heritage
The Indian mathematical tradition is one of the richest and most consequential in human history. Its contributions (the decimal system, zero, negative numbers, infinite series, solutions to Diophantine equations, trigonometric tables) form part of the foundation on which all modern mathematics is built. And its greatest figures (Aryabhata, Brahmagupta, Madhava, Ramanujan) rank among the most brilliant mathematicians of any civilization.
That this tradition is not better known outside India is a consequence of historical circumstance rather than of intellectual merit. The transmission of Indian mathematics to Europe was indirect and slow, filtered through Arabic intermediaries who sometimes received credit for ideas they had transmitted rather than originated. The Kerala school’s anticipation of calculus was not known to European scholars until the twentieth century. Ramanujan’s genius was recognized by the mathematical community during his lifetime, but his early death cut short a career that might have reshaped entire fields.
Today, India produces more mathematicians and computer scientists than any other country. The tradition that began with Aryabhata’s sine tables and Brahmagupta’s rules for zero continues in research laboratories, universities, and technology companies worldwide. The numerals are Indian. The zero is Indian. The infinite series are Indian. The tradition is alive, and its best work may still lie ahead.