Errors in mathematics are common hurdles for teachers and students; therefore, it is important to learn what errors students make and how students treat them. This study initially identified the types of errors students made while working with algebraic expressions and documented and analyzed the process of students completing an error analysis assignment using one of two different support tools provided. Using a descriptive quantitative design, a detailed account of the students' error analysis process was developed. Students were assigned a formative assessment that showed how the students performed and what types of errors the students made. The average quiz score was 50%. The whole group of 18 students made 111 errors. The average number of errors was six per student. Findings show that students made the most errors while working on factoring tasks (41.4%). Next, the students made combining like terms errors (30.6%). The students made the fewest errors while working on distribution tasks (17.1%). Students were assigned an error analysis assignment with integrated support tool. The Answer Key and Word Bank students were asked to write the errors they made for each incorrect question and incorporate the word bank vocabulary. Their responses support the conclusion that all the students understood the error analysis task. The Error Sentence Samples students were asked to select all the error sentences that applied to the errors they made for each incorrect question. The students had little success in correctly identifying their errors. The majority of the students' errors were left unidentified, and the students considerably over-selected errors beyond their actual errors made. The 12 students who completed the error analysis assignment made 63 errors overall, and each support group made approximately the same number of errors. The Answer Key and Work Bank group found a greater percent of their errors at 30% found, while the Error Sentence Samples group found 20%. This study determined that students need increased practice and scaffolding to find their errors, and that researchers should study error analysis done in a traditional learning environment and gather student feedback about the error analysis usefulness. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]