Photo/IllutrationFourth- and fifth-grade primary school students participate in the national abacus competition in Nuku’alofa, Tonga, on March 22. (Tetsuo Kogure)

NUKU’ALOFA--The “soroban” Japanese abacus has been an indispensable part of math education in Japan for centuries, and although eclipsed by electric calculators at home in recent years, it has become an essential tool for teaching mathematics in Tonga.

More and more children in the Pacific island nation are getting their hands on a soroban every year thanks to governmental support, Japanese volunteers and donations of used abacuses that have continued for more than 40 years.

Here in the capital of a nation with a little over 100,000 people, a class of third-graders at Ngele’ia Primary School was holding abacuses and listening to a teacher’s instruction.

“Use the thumb to add, and the index finger to subtract,” said Mavaetangi Siolaa’ demonstrating to the class.

After going through an assignment sheet of adding and subtracting questions, a student selected by the teacher used a large soroban in front of the class to check answers.

“It is fun to calculate using fingers,” said 8-year-old Ula Kaivelata. “I want to be able to solve harder calculations.”

Tonga has adopted the soroban as a compulsory part of mathematics education for third- to fifth-graders at primary schools since 2009.

Soroban lessons are given in those grades every day for 15 minutes. In fifth grade, students are taught multiplication and division by up to three digits. At teachers’ colleges, abacus teaching methodology is a compulsory subject.

The eighth national abacus competition was held here in Nuku’alofa on March 22, with about 200 fourth- or fifth-graders who won regional competitions taking part.

The participants were tasked with solving 100 calculation questions involving up to five digits within eight minutes.

The competition was co-hosted by Tonga’s Ministry of Education and Training and the Embassy of Japan in Tonga.

The Tongan government’s aim to raise students’ basic mathematics abilities by teaching using the soroban seems to be working slowly but surely.

According to the education ministry, the percentage of sixth-graders who scored 50 percent or above on a national general exam in math greatly improved in less than 10 years. It was 15 percent in 2010 and 11 percent in 2011, just one and two years after the nationwide introduction of abacus education. In 2016 and 2017, it was 27 percent and 21 percent, respectively.

Ministry official Loani Tahitua, who is in charge of abacus education, said using the device can nurture children’s concentration abilities as it trains them to solve assignments carefully within a short time limit, and that mastering mental calculation by picturing soroban in their head also helps train the memory.

According to Masao Fujii, 74, director-general of the International Soroban Diffusion Foundation (ISDF), a Tokyo-based nonprofit organization, soroban use took off in Tonga when the late Toshio Nakano, who was teaching at Daito Bunka University and used to run a private abacus school, was invited to the nation by Tupou IV, the Tongan king at the time, in 1976.

The king was considering introducing the soroban in local schools to improve academic standards in math, as he had learned to use the device from a Japanese businessman when he was young. He asked Nakano, who was a professor emeritus at Daito Bunka University at the time of his death, to instruct Tongan teachers in teaching the soroban to children.

The following year, Nakano returned Tonga with a dozen or so abacus teachers, including Fujii, to provide training to local teachers for a week.

“I only expected it to go on for four or five years at the longest,” said Fujii. Despite his pessimism, the exchange has continued to this date.

From 1989, the Japan International Cooperation Agency (JICA) started sending Japan Overseas Cooperation Volunteers, who are skilled in the abacus, to Tonga.

Many soroban used in public schools here are secondhand ones donated from Japan.

The city government of Ono, Hyogo Prefecture, which is the major abacus production center, has donated more than 6,600 abacuses in total to Tonga since 2011.