The Education system in Germany recently invested five billion euro in digital infrastructure for 40 000 schools. Therefore, this mixed-method study explored the relationship between integrating educational technology in mathematics education and the mathematics achievement of Grade 4 German students. Descriptive statistics and two-level Hierarchical Linear Models (HLM) were used to analyse the Trends in Mathematics and Science Study (TIMSS) 2015 questionnaire data of students, their parents, mathematics teachers and principals. Semi-structured interviews and classroom observations were also used to collect data at two schools, which were conveniently and purposefully selected. Findings from HLM revealed that students who owned a mobile phone, a computer/tablet as well as those who used computers/tablets ‘every or almost every day’ at home, at school and other places for schoolwork, achieved lower mathematics scores than their counterparts. While the shared use of a computer/tablet and an internet connection positively and significantly predict student performances.