The RADEC learning model is a learning model that can improve critical thinking skills whose application is still being studied in schools. This quantitative research study aims to describe the effectiveness of applying the RADEC learning model in improving science learning outcomes for fourth-grade elementary school students. This study (pseudo-experimental design) involved 82 students consisting of 3 classes (Class IVA = 29 students, Class IVB = 25 students, and Class IVC = 28 students). Based on the random sampling technique, class IV A was obtained as the experimental class and class IVB as the control class. Science learning outcomes data were collected using a description test. The collected data were analyzed using descriptive statistics in the form of averages and statistical tests using the t-test (independent sample t-test) and N-gain. Based on the results of hypothesis testing, the sig. (2-tailed) = 0.00 < 0.05. The average value of the experimental class is 81.24 and the average value of the control class is 68.20. Furthermore, based on the N-gain test, an average N-gain value of 0.56 is obtained or is in the medium category. Thus it can be concluded that there are differences in student learning outcomes that apply the RADEC model to conventional learning models. Therefore the RADEC learning model is important to be applied in education because it can improve student learning outcomes.