How does an abacus work?

Question

I just want the main things like how to add and subtract. I've tried going to some site but their defintions are really hard to understand so i want a simplified verision.

Answer 1

Use an abacus just like how we count, for example:

Start on the far right side and count from right to left. The first right column is the one's column, the second right column is the ten's column, the third column is the 100's column, etc.

See link below for further instructions.