Soroban is considered as the first calculator in Japan. It’s a bar and normally 33 X 6 cm. It has beads and people slide the beads to calculate. Soroban calculates based on the decimal system.
As its benefits, it fosters a sense of numbers, helps understanding of calculation process, develops mental calculation, and so on. Many parents have children to learn soroban.
When I was a student, classmates who learn soroban had an amazing speed (to me) to calculate numbers even without using a pen & a note. They can calculate numbers in their mind! I thought “I wish my parents had me go to a soloban school.”