The purpose of this investigation is to ascertain the level of analytical reasoning abilities possessed by students in the context of the resolution of mathematical problems involving reasonable inequalities involving a single variable. This study is a qualitative investigation on descriptive issues. Students from class X IPS 1 at SMA Santo Fransiskus Asisi Pontianak volunteered to participate in the study as research subjects. A test of one's ability to think critically is included in the data gathering instrument. The analysis of the data began with a categorization of each piece of information according to the amount of critical thinking it required, as determined by Ferret's critical thinking markers. According to the findings of a study that involved 29 students, the majority of students in class X IPS 1 SMA Santo Fransiskus Asisi Pontianak are at level 1 in terms of their critical thinking. The study found that 28 students, or 96 percent, thought uncritically, while only one student, or 1 percent, thought critically enough. These findings led the researchers to draw the conclusion that the majority of students in this class are at level 1. (not critical).
