Addition and Subtraction with a Counting Board This method is used to help mathematics students to understand the meaning of arithmetic. This method is called counting board. The counting board is a nice simple one and interesting to learn about. The counting board is quite a simple device. It is a way of extending the method of adding by piles of pebbles to larger numbers without having to use many pebbles. The idea is that pebbles on one line stand for just what they are, one pebble, but pebbles on other lines stand for different numbers of pebbles, 10, 100, 1000 pebbles. You can make a counting board for yourself by drawing lines on an ordinary piece of paper like this.
M C X I Example for using a counting board = one = ten= hundred = thousand