The research aimed to identify "the effectiveness of educational-learning design according to the model of brain compatibility in achievement among firstmiddle grade students in mathematics", in schools affiliated with the Second Karkh Directorate of Education. To achieve the goal of research, the following zero hypothesis has been formulated: " There is no statistically significant difference at the semantic level (05.0) between the average scores of experimental group students who will study with design accreditation (educational - learning) according to the brain compatibility model and the grades of control group students who will study in the usual way in the achievement thinking test". The research community, which is represented by the middle and secondary schools for girls belonging to the General Directorate of Education of the Second College, was selected (Medium Al-Janain for Girls), and the research sample consisted of (75) female students (first intermediate grade) with (37) students for the experimental group, and (38) students for the control group. For the purpose of verifying the research hypothesis, the achievement test was built, as the test in its final form is (38) paragraphs of the objective type. Appropriate statistical analyses (difficulty and ease coefficients, discrimination coefficient, and effectiveness of wrong alternatives) were carried out, and their cyometric characteristics were confirmed, after the statistical tools were selected to analyze the results of the application of the test, and the test (t-test) was used. The results indicated: Experimental group students who studied according to the brain compatibility model outperformed the control group students who studied according to the usual method of achievement test