I got this super bargain: a miniature 15 column copper beads abacus mounted on a stab of marble at local flea market a couple of months ago. That is a treasure of its kind.
I don't think I've ever learned how to do square root and cubic root on a Chinese abacus. I did know it also does hexadecimal calculations. Traditional Chinese weighing units was a hexadecimal system. One jin (斤) equals sixteen liang (兩). Abaci were commonly used in market place to calculate with these hexadecimal units. When all the beads in the Chinese abacus are used, each column can be used to represent numbers between 0 to 15 (two 5s and five 1s.) Computation in decimal and hexadecimal is very similar except one extra bead from both the upper and lower deck are used.