In this study, it was aimed to investigate possible impact of using the KWL reading strategy in teaching the topic of "fractions and operations with fractions" to the 4th graders on students' problem-solving achievement. A quasi-experimental design with pretest-posttest control group (CG) was employed in the study. The study group consisted of 35 4th graders studying at a primary school in Bartin, Turkey. In the research, an experimental group (EG) and a control group (CG) were used. There were 18 students in the experimental group (EG) and 17 students in the control group (CG). The test of equivalency (TE), Problem-Solving Achievement Test (PSAT) to gauge effect of instruction with the KWL strategy and reading texts were employed as data collection tools. The Wilcoxon Signed Rank Test and Mann Whitney U Test were employed in the research. It was found as a result of the research that the KWL strategy fostered the students' problem-solving achievement. However, there were no significant differences between the EG and CG in terms of the scores received in the step of implementing the plan.