This paper is a report of a doctoral thesis that investigated the factors that were associated with the use of computers in secondary mathematics teaching, the choices made by teachers and learning theories guiding their teaching. Mixed methods approaches were used to triangulate the results of the study. The study was divided into three stages, the first a questionnaire completed by 114 teachers, the second was examination of current accredited courses in teacher preparation for mathematics teaching to identify what learning theories were included in subjects, and the third were interviews with 8 teachers in training and 6 experienced teachers. Results of the inquiry revealed that the probability of a teacher using a computer was maximized when they strongly agreed with the statement that the lack of lesson plans was a barrier to using computers and with the belief mathematics is made up of individual components and responded highly undesirable in training conducted by the Internet or education department training programs and strongly disagreed with the belief that when teachers use computers in the classroom, they are able to spend more time on concepts. Overall, the teachers made choices to use computers when appropriate in their lesson preparation, teaching materials and teaching strategies with the use of learning theories.