A Written method of addition may fall into one of two types; formal and informal methods. The vid.eos below, give examples of both types
Informal method of addition
This video demonstrates two informal methods of carrying out addition. The first method is based on partitioning each of the numbers, adding up the corresponding values then totalling the result to give the final answer. The second method uses a blank number line for counting and recording results.
Formal method of addition
This video demonstrates how to add using the column method. In this method, numbers are stacked one above the other so that the decimal points (if used) and the digits of each number are aligned according to the rules of place value.