Suanpan dating from around 1985

This Chinese abacus with red lacquered beads has thirteen places. It is a classical suanpan with five unit-beads per rod below the horizontal bar and two fiver-beads per rod above the bar. Starting from the right, the first rod counts the units, the next one counts the tens, the next the hundreds, and so on. If necessary, the units-rod can be moved to the left, so that decimal places can be accommodated. By a clever method of bundling results, the suanpan enables the skilled user to perform all four operations of arithmetic.