[dan-robertson]

I think that was the old solution: they have a large tray with 100 slots and a bar which allows for multiples of 10 to be counted. The digits are done manually. The problem was that pearls could fall out of the tray and, as they are round, roll around on the floor taking up to 30m to find. It is a mechanism for counting out a specified number rather than determining how many are in a bag, which may be more limited. Another problem was that if workers forgot the partial sum, they would need to start again.