The lower mathematical reasoning abilities of elementary school students are the
background of this research. This happens because students have not been properly
facilitated to develop the ability mathematical of reasoning. Mathematics learning can
develop reasoning ability well because mathematics learning has systematic concepts and
conceptual relationships. This will have an impact on logical, systematic and rational ways
of thinking. Therefore, teachers must be able to choose learning models that can facilitate
the ability of mathematical reasoning. One learning model that can be used is the literacy
project-based learning model. This study aimed to determine the effectiveness of improving
the ability of mathematical reasoning students who obtain literacy project-based learning.
The design of this research was used pretest-posttest non-equivalent control group. Based
on research results, conclusions can be drawn about the effectiveness of learning that
includes n-gain, minimum completeness criteria, and mastery learning. Literacy projectbased learning has been effective in facilitating reasoning abilities. That is because literacy
project-based learning can present contextual material with literacy works that are made and
invited to carry out the process of thinking about the use of mathematical contexts in daily
life. Furthermore, students can connect mathematical material with real-life contexts and
can make reasoning to interpret learning well.