Bhowanipore: The 125th birth anniversary of Keshab Chandra Nag, a name synonymous with mathematics textbooks in Bengal, was on Friday celebrated by a heritage Calcutta school where he had spent about four decades teaching the subject.

The quasquicentennial event organised by Mitra Institution, Bhowanipore, was appropriately all about numbers and Nag's scholarship and lifelong effort to ease the burden of mathematics on generations of students from classes IV to XII.

"There have been many stars in the history of Mitra Institution, but Keshab Chandra Nag is one of its diamonds. He was the headmaster of this school during the last few years of his service," Asit Baran Giri, the current headmaster, said at Rabindra Sadan.

Publishing lore has it that Nag started converting his handwritten notes into textbooks on the advice of the novelist Sarat Chandra Chattopadhyay. It helped that a publisher saw in him the potential to be a prolific textbook writer, someone who would go on to release 47 titles since his first one came out in the Fifties.

The first few texts were in Bengali, but Nag soon started writing them in English as well. Their success spawned editions in Hindi, Urdu and even Braille. "Eighteen of those textbooks are still in circulation, garnering about Rs 6 lakh in royalty every year," said Tridibesh Nag, a grandson of Nag.

According to a bookstore owner, demand for mathematics textbooks by Nag isn't restricted to students of schools affiliated to the state secondary and higher secondary education boards. "They remain just as popular among students of other boards, which the sales figures reflect," he said

Born in 1893 at Gurap in Hooghly district, Nag was the quintessential Bengali in his choices - an ardent Mohun Bagan supporter, an Uttam-Suchitra admirer, a devotee of the Ramakrishna Mission, a freedom fighter and a social worker.

"Keshab Chandra Nag, to my mind, did not get the recognition he deserved in his lifetime. We appeal to the central and state governments to correct this anomaly at the earliest," said a member of the alumni group Amra Sobai Mitra 1981.

Dipak Kar, the pro-vice-chancellor of Calcutta University, and several professors of the institution's mathematics department spoke on Nag's contributions to the study of a subject that is loved, hated and feared by students in equal measure.

Amra Sobai Mitra 1981 presented the KC Nag Awards to a few meritorious students of their alma mater, especially those who have excelled in mathematics.