%center% http://meta-studies.net/pmwiki/uploads/Abacus.jpg

This is a contemporary Chinese abacus of the type used in multiple settings in Asia.    The columns are arranged so that on the right-most the unit is 1, the next left the unit is 10, and so on.  The top panel contains columns each of two beads where the movement of one bead represents an addition (or subtraction) of five of the unit represented by the column.  For the columns of beads in the lower panel, movement of a bead represents addition (or subtraction) of one of the unit represented by the column.