<![CDATA[The ability to use mathematics to understand and solve contextual problems is an essential competency that needs to be developed in undergraduate Basic Mathematics courses. Learning should provide students with opportunities not only to master mathematical concepts and procedures but also to apply their mathematical knowledge in meaningful situations. This study aimed to describe the improvement in students’ mathematical literacy after participating in Problem-Based Learning (PBL) and to examine this improvement according to students’ initial mathematical ability, as measured by their pretest scores. The study employed a descriptive quantitative approach with a one-group pretest–posttest design. The participants were 37 students enrolled in the Science Education Study Program who were taking a Basic Mathematics course covering the topic of ratios. Data were collected using a constructed-response mathematical literacy test administered before and after the learning intervention. The research procedure consisted of one pretest session, four sessions of Problem-Based Learning, and one posttest session. The data were analyzed descriptively using minimum and maximum scores, means, standard deviations, and normalized gain (N-gain), with the results further described according to initial mathematical ability groups. The results showed that the mean score increased from 61.51 on the pretest to 80.08 on the posttest, representing an improvement of 18.57 points and an N-gain of 0.48, which falls within the moderate category. Improvements were also observed among students with low, moderate, and high initial mathematical ability, with respective N-gain values of 0.47, 0.50, and 0.47, all of which were in the moderate category. These findings indicate that Problem-Based Learning has the potential to support the development of mathematical literacy among students with diverse levels of initial mathematical ability. The findings may inform the design of Basic Mathematics instruction that integrates contextual problems and takes students’ initial abilities into consideration.]]>
