The conclusions drawn from the study were consistent with the predictions of SDT. First, intrinsic motivation positively affected math performance (β=7.865), whereas external regulation negatively affected math performance (β= -15.196), consistent with the first hypothesis (H1). Math self-concept positively affected math performance (β=11.399), consistent with the second hypothesis (H2). Autonomy support positively affected math self-concept (β=0.072) and math performance (β=1.474), consistent with the third hypothesis (H3). Math self-concept significantly affected math performance through the mediator of intrinsic motivation, consistent with the fourth hypothesis (H4). Finally, autonomy support in the classroom significantly affected math performance through the mediator of math self-concept, consistent with the fifth hypothesis (H5).