The broad purpose of this research is to gain a holistic understanding of teachers' integration of technology into classroom practices. This research examined a case of a secondary school mathematics teacher's classroom teaching in England in which a web-based dynamic mathematical tool, the Cornerstone Maths software, was used in the teaching of the subject of geometric similarity. One of the contemporary theoretical frameworks, The Structuring Features of Classroom Practices (SFCP) (Ruthven, 2014), guided my research with its five different components related to the integration of new technologies into classroom practice. Classroom observation and semi-structured post-lesson teacher interview was employed for data collection. The analyses showed how the teacher used the Cornerstone Maths software to teach geometric similarity in terms of five underlined features of classroom practice within the SFCP model.