W390xL70xH20mm, Japan
This is a Soroban. A calculation device. The Japanese version of the abacus. The number of rods are always of odd number, starting from 13, then 21, 23, 27 (this one) and going up all the way to 31. The more rods will allow for more digits in the calculation. The beads on the rods are separated in 2 rows by the reckoning bar; on each rod below the bar are 4 earth beads, above it there is 1 heaven bead. Each rod represent the same digit, with 1 heaven bead = 5 earth beads, so each rod can go up to 9 before moving to the next digit. The Soroban is still currently in use in Japan, it is reinforced by being taught at school and as part of the entrance requirement to public cooperation.
Mountain Folkcraft 