The world's first "wearable computing" device was the Chinese abacus

The fashion of wearable devices has recently swept through the world of consumer electronics, but the trend may have been earlier than we thought, and today we're going to introduce a 17th century wearable device: Yes, the abacus, 300 years ago in the Qing Dynasty, The industrious and courageous Chinese working people have already created this wearable abacus, which is definitely the earliest "wearable calculation" in the world. The abacus on the ring is 1.2 cm long and 0.7 cm wide. Although the size is very small, but the function of the abacus is absolutely complete, as long as casually with a bun and other things can be fiddle, is probably used by ancient businessmen, using its portable characteristics, do some business transactions in the mathematical calculations. The abacus would have been better if the designer had thought of the wrist watch. Do you think about the abacus when you were in primary school?