The purpose of this research study was to investigate and classify particular categories of mathematical errors made by students with Limited English Proficiency. Participants included 15 general education teachers, two English as Second Language teachers, and 91 Limited English Proficiency students. General education teachers provided mathematics worksheets to participating students at least once a week over a period of two months. This instrument was evaluated prior to the research study by a panel of experts who provided an average content validity (CVI greater than 0.80) and inter-rater reliability (IRA greater than 0.80). Students' worksheets were analyzed using chi-square and frequency distribution statistical methods. The outcomes of this study will not only help teachers identify common and uncommon computation error patterns across ethnic groups and grade levels, but also provide useful information by which education educators can develop effective intervention strategies for mathematics instruction.