Practice is essential to improve learners' acquisition of mathematical knowledge and skills. For the freshman Mathematics module in a Polytechnic in Singapore, exercise questions in PDF format have been provided as a form of further practice, which learners solve, after class, in their own time. This approach also attempts to foster students' self-directed learning (SDL) abilities. As technology advances, e-learning platforms can be utilised, along with adaptive learning technology, to enhance learners' engagement and independence in solving these exercises or practice questions. Our study adopted a quantitative research design to examine the impact of an in-house creation of interactive online exercises in the Sharable Content Object Reference Model (SCORM) format on 2383 learners' SDL abilities, mathematical knowledge, and skills. The design of the SCORM exercises incorporated the seven factors guided by an SDL index (Vedamuthu & Periasamy, 2022): Assess Task, Evaluate Expertise, Plan Approach, Monitor Progress, Adjust Strategies, Learning Motivation and Collaborative Communication. Independent sample t-tests were conducted on the assessment scores and raw module scores of learners who completed six or more SCORM exercises compared to those who completed three or fewer SCORM exercises. In addition, a paired sample t-test was carried out on the pre-SDL and post-SDL survey scores of learners who completed six or more SCORM exercises. Results from both sets of tests reveal that learners who attempted six or more SCORM exercises have significantly improved their mathematical knowledge, skills, and SDL abilities. It is recommended that interactive online exercises in SCORM format be included in technical modules to improve learners' academic performance and SDL abilities significantly.