The purpose of this study was to survey and examine the history of teaching of the basic addition facts in elementary school mathematics in the United States from colonial times to 1950. This examination is intended to provide insight into the causes of frustrations in teaching the facts in the past and possibly serve to alleviate anxiety in the search for the "best" method. Besides the survey, a comparison was made of the difficulty ranking of basic addition facts found in previous research to that made from a test given to 443 second-grade students. This comparison was made to measure the effect of the current emphasis on structure in teaching mathematics. The results of the comparison supported the hypothesis that changes in the difficulty order of the facts are reflective of different methods for teaching them. (JP)