Math section of September mock CSAT similar to last year's exam

The mathematics section of the September mock College Scholastic Ability Test for the 2027 academic year, held Wednesday, was assessed as comparable in difficulty to both last year's September mock exam and the actual CSAT.

In its analysis of the math section's question trends, EBS said the exam appeared designed to secure differentiation among mid-tier students through moderate-to-high difficulty questions requiring precise understanding and application of given conditions. However, it noted that some questions may have felt somewhat challenging due to the need for comprehensive thinking skills.

A notable feature of this year's September mock math section was an increase in questions assessing students' ability to analyze function graphs, compared with last year's CSAT.

Many questions required the comprehensive application of mathematical concepts, principles and rules, or logical reasoning based on given situations. EBS said questions demanding excessively complex calculations, disproportionate solving time, or rote problem-solving techniques drilled through private tutoring were excluded.

Among the common subjects, question 22 in Mathematics I and question 21 in Mathematics II were identified as the top differentiating items. Question 22, which involves applying the relationship between exponential and logarithmic functions and parallel shifts of graphs, was seen as intended to distinguish top-tier students. Question 21 required students to infer the shape of a function's graph based on an understanding of differentiability and analyze it comprehensively.

In the elective subjects, question 30 in Probability and Statistics, question 28 in Calculus and question 30 in Geometry were expected to have relatively high differentiating power. Question 30 in Probability and Statistics required an understanding of the relationship between sample means and population means. Question 28 in Calculus called for finding the relationship between functions representing the area and angle of a figure and applying implicit differentiation, while question 30 in Geometry asked students to analyze vectors satisfying given conditions to find the value of a dot product.

EBS assessed that even these questions were based on concepts covered in the school curriculum and EBS CSAT-linked study materials. It said the ability to accurately understand fundamental concepts and apply them to the conditions of each problem was more important than memorizing problem-solving techniques.

The EBS linkage rate stood at 50 percent, with 15 of the 30 total questions linked to EBS materials. In the common subjects, 11 questions were linked — five from Mathematics I and six from Mathematics II — while four questions each were linked in the elective subjects of Probability and Statistics, Calculus and Geometry. Various linkage methods were applied, including the use of concepts and principles, modified questions, and the use of data and situational contexts.

EBS advised students to "thoroughly review a wide range of concepts without focusing too heavily on any particular unit" in their remaining CSAT preparation, adding that "it is also important to carefully analyze the conditions of each case rather than jumping to an answer based on a specific assumed scenario."