This study compares two E-learning environments: E-learning supported with IMPROVE self-metacognitive questioning (EL+IMP), and E-learning without explicit support of self-regulation (EL). The effects were compared between mathematical problem-solving and self-regulated learning (SRL). Participants were 65 ninth-grade students who studied linear function in Israeli junior high schools. Results showed that EL+IMP students significantly outperformed the EL students in problem-solving procedural and transfer tasks regarding mathematical explanations. We also found that the EL+IMP students outperformed their counterparts in using self-monitoring strategies during problem solving. This study discusses both the practical and theoretical implications of supporting SRL in mathematical E-learning environments.