This study, anchored on the Theory of Implementation (May, 2013) and the Theory of Dis-capability (Bellanca et al., 2011), sought to determine the association between the level of challenges of the transition phase and the extent of students learning development in Mathematics in order to craft a proposed plan on curriculum implementation. Using a researcher-made, expert-validated survey questionnaire data were gathered from 47 teachers in Cluster 4. It was found that schools have high levels of challenges in the transition phases, particularly in time allotment and student readiness. The study also found that the extent of student development was moderately observed across four variables but highest in interest and attitude. However, no significant correlation between the level of challenges of the transition phase and the extent of students learning development was established. The researcher recommended technical assistance to schools in budgeting time for classes and in providing support to learners during the adjustment period more meaningful and enjoyable learning activities that would help learners appreciate learning better internal and external support to overcome the challenges of the transition and qualitative study to investigate lived experiences of teachers or learners during the transition phase.