Formative assessment is indeed a hot issue at the moment. Primary schools in Hong Kong are now paying more attention to the topic and are hoping to create an appropriate assessment for learning. E-Learning can certainly play a serious role in the syllabus for KS2. Therefore, we believe that e-Assessment is one of the valuable assessment tools that can facilitate assessment for learning continuously by collecting real-time learning data and giving immediate feedback. So that we can promote learning efficiency in primary schools, especially for senior primary students. Hence, our school decided to use free online e-assessment tools in the mathematics classrooms from P.4 to P.6 since 2015. This practice does not only increase students’ motivation, it also further improve assessment method. For no doubt, Technology-Enhanced Assessment Tool is one of the most feasible solution to facilitate assessment for learning for the general primary schools in Hong Kong.