Students' sound knowledge of mathematical concepts is important for the development of their mathematical knowledge to support the more challenging application skills at higher levels of mathematics learning. Diverse classroom teaching strategies with appropriate teaching tools are crucial to ensure that students meaningfully achieved the set learning outcomes. The use of web 2.0 tools enabled students to communicate actively with their peers and teachers during lessons. This quasi-experimental study with a mixed method approach involving pre-test and post-test was conducted to examine the effect of using web 2.0 tools on students' mathematical achievement. 60 Year Five students were randomly divided into two groups, namely the control and the experimental groups. The experimental group was taught using the Direct Instruction (DI) Model of teaching strategy with web 2.0 tools while the control group was taught using the DI Model of teaching strategy without web 2.0 tools. The teaching strategy that used web 2.0 tools has not only brought about the increase in students' mathematics achievement but has also motivated them to complete the tasks given during the lessons. The findings of this study also showed that students' learning of mathematics in the classroom was fun and they became more interested with the usage of 2.0 tools. So, mathematics teachers need to be continuously trained to enhance their teaching competence to meet the challenges of incorporating technology in their classrooms.