This article assessed one objective derived from an unpublished master's thesis with the title "Factors Constraining the Effective Application of Information and Communication Technology (ICT) in Teaching and Learning Mathematics: Case Study of Selected Secondary Schools in Rwanda." The objective of this study was to investigate how mathematics teachers perceive the use of technological tools in teaching and learning mathematics. Gregory's constructivist theory of perception served as the anchor for the research. A case study research design was adopted. The research focused on secondary school mathematics teachers in 10 selected Rwandan schools. Purposive sampling was employed to choose 20 mathematics teachers. Primary data was obtained through open-ended questionnaires along with semi-structured interviews, and thematic analysis was employed for data analysis. Study outcomes indicated that perceptions of mathematics teachers' of embracing technological tools are formed by their familiarity with technology, confidence in adopting it, and the help they get in incorporating it into their teaching procedures. The study concluded that teachers ought to participate in Continuous Professional Development (CPD) programs aimed at technological tools to enhance confidence and boost their integration into teaching. According to research, school leaders should ensure access to the most up-to-date technological resources and offer customized training to facilitate effective technology adoption in mathematics teaching. The study further suggested that Rwanda Basic Education Board (REB) and the National Examination and Schools Inspection Authority (NESA) should enforce extensive training programs, avail more resources in essential technological infrastructure, and boost research and best practices to encourage innovation. Additional research should broaden its context to include different perspectives, evaluate the long-term impact of technological tools on student outcomes, and assess the effectiveness of professional development programs.