MARINE CORPS AIR STATION IWAKUNI, Japan -- Miyuki Inoashi, a master teacher of soroban, visited the Matthew C. Perry Elementary School to train students in the art of the soroban here Nov. 16.
Soroban is an advanced mathematical tool supporting one’s mental calculation aptitude and facilitates a better understanding of the number concept, base ten systems and place value.
The physical soroban itself is composed of an odd number of columns or rods, each having beads: one bead has a value of five, called a heavenly bead, and four beads have a value of one, called earth beads.
Each set of beads of each rod is divided by a bar known as a reckoning bar. The tool is used to calculate various types of mathematical equations.
Inoashi asked several students in a fourth-grade class their favorite two-digit number and wrote them on the white board in front of the students.
She then added a third digit to each number and challenged Yoko Hamagiri, the Japanese Culture and Language teacher for M.C. Perry Elementary School, to a race to see who could add them up the fastest.
“Watch her carefully, so you can see how she uses her special tool,” Hamagiri told her class.
With calculator in hand, Hamagiri tried to input each number as quickly as possible but Inoashi’s fingers raced up and down, side to side across the abacus-like frame.
By the time Hamagiri finished the addition problem with a calculator, Inoashi had gotten the answer four times with her soroban. The answer was 4,285.
Inoashi then asked another student to choose a random addition problem from a book.
Hamagiri wrote it on the white board yet again.
She then told the class that she would find the answer without using her soroban and instead visualize the soroban to solve the problem.
While Hamagiri tried again with her calculator, Inoashi used the mental calculation skills gained from practicing soroban and finished the equation far before Hamagiri could even input the whole problem.
“My mother was a soroban teacher,” said Inoashi. “She started teaching me when I was only 6 years old. Since then I have been practicing for two to three hours each day.”
She taught the students how to use the soroban by demonstrating on a much larger version while they practiced with smaller versions.
They learned how to do basic addition and subtraction problems for one- to four-digit numbers.
The soroban can be used for addition, subtraction, multiplication and division.
The tool is often taught in primary schools during mathematical lessons because the decimal number system can be demonstrated visually.
As Inoashi taught the class, the students caught on quickly and enjoyed the lesson.
“It was a lot of fun,” said Kamar Brown, a fourth-grader at M.C. Perry. “It’s a lot faster and with practice you can even beat a calculator. I wish they had more classes like these because they only have them once a year.”
Through just a short 40-minute session with Inoashi, students became more comfortable using the soroban and learned simple ways to calculate complex figures.