The research aimed to identify “The impact of an instructional-learning design based on the brain- compatible model in systemic thinking among first intermediate grade female students in Mathematics”, in the day schools of the second Karkh Educational directorate.In order to achieve the research objective, the following null hypothesis was formulated:There is no statistically significant difference at the significance level (0.05) among the average scores of the experimental group students who will be taught by applying an (instructional- learning) design based to on the brain–compatible model and the average scores of the control group students who will be taught through the traditional method in the systemic thinking test.The research community was determined and represented by the intermediate and secondary day schools for girls within the Karkh II general educational directorate, and Al-Jana in Intermediate School for girls was selected, the research sample consisted of (75) female students from the first intermediate grade that were distributed as (37) students female in the first experimental group, and (38) in the control group.For the purpose of the research hypothesis testing, a systemic thinking test was built, as the test in its final form consisted of (24) essay items with restricted answers, and the test was divided into ( (2) items for each sub-skill).The appropriate statistical analysis were carried out (the difficulty coefficient and coefficient of ease, the discrimination coefficient, and the effect of wrong alternatives), and their psychometric properties were ascertained,after the statistical tools were chosen to analyze the results of the application of the test, such as using the (t-test), and the results indicated:The experimental group students who studied according to the brain concordance model out performed in the systemic thinking test on the control group students who studied according to the traditional method.