The integration of mathematics and science in teaching facilitates student learning, engagement, motivation, problem-solving, critical thinking, and real-life application. Although curriculum integration is theoretically desirable for many educators, what to integrate and how to integrate are often the big questions facing teachers working within education systems premised on a culture of segregated subject delivery. This quasi-experimental study reports on a 2-week inquiry of the implementation of an integrated unit of learning on motion problems, within upper secondary education in Turkey. In order to reveal the effect of the instruction on students with different mathematics achievements, the study was conducted with 131 students in two different schools. In the design of the integrated unit, continuum model of learning and four-stages of learning model were employed. The study employed a quantitative approach and examined the key aspects of the practice of the integration of mathematics and science teaching. In light of the data obtained, it was concluded that teaching the subject Motion Problems through an integrated design had a positive effect on students' learning for the experimental groups in each school.