This study aims to help concrete thinkers learn science through the use of Piagets' cognitive processes (CPs) during scientific inquiry. A total of 203 fourth-grade students participated as volunteers in a pre-post control group study. The students were from urban, remote rural, and suburban regions of Indonesia. Data analysis demonstrated that students were at a low level of concrete reasoning. However, CPs significantly enhanced students' academic performance in science classes from low to medium and even high categories. CPs also promoted concrete thinkers from lower to higher levels of concrete reasoning. Study results suggest that teachers should attend to the concrete reasoning development of elementary school students and promote their levels of cognitive processing to help them achieve academically in science.