(Description) Figure _unit9.2.3 Figure 8 A mechanical procedure for column addition: carry out the addition following some simple rules: Start at the right-hand column. Add the numbers in that column. Write the total at the bottom of the column. If the total is greater than 9, cross out the 1 and add it to the total of the next column. Proceed with the next column (from right to left).

Digital thinking tools for better decision making

A figure showing a column addition, with columns for 1’s, 10’s and 100’s (from right to left).