Mathematical literacy is defined as one’s ability to formulate, apply, and interpret mathematics in the real world. Ethnomathematics is a daily mathematical representation or mathematics associated with cultures used to motivate students to learn. This qualitative descriptive aims to describe the mathematical literacy of Year 10 students of Senior High School 1 Sidoarjo in solving ethnomathematics problems related to batik Sidoarjo. Five students were selected using a purposive sampling technique. Data were collected through a mathematical literacy test and interview. The test and interview results were analyzed utilizing a triangulation method proposed by Miles, Huberman, and Saldana. The findings revealed that, in general, Year 10 students of Senior High School 1 Sidoarjo performed adequate mathematical literacy. Teachers need to pay great attention to designing mathematical literacy problems to accustom students to solve mathematical problems in their surroundings.

Mathematics inequality is an essential concept that students should fully understand since it is required in mathematical modeling and linear programming. However, students tend to perceive the solution of the inequalities problem without considering what the solution of inequality means. This study aims to describe students’ mistakes variations in solving mathematical inequality. It is necessary since solving inequality is a necessity for students to solve everyday problems modeled in mathematics. Thirty-eight female and male students of 12th-grade who have studied inequalities are involved in this study. They are given three inequality problems which are designed to find out students’ mistakes related to the change of inequality sign, determine the solution, and involve absolute value. All student work documents were analyzed for errors and misconceptions that emerged and then categorized based on the type of error, namely errors in applying inequality rules, errors in algebraic operations, or errors in determining the solution set, then described. The result shows that there were some errors and misconceptions that students made caused by still bringing the concept of equality when solving the inequalities problem. It made them did not aware of the inequality sign. Students are still less thorough in operating algebra and do not understand the number line concept in solving inequalities. The other factor was giving “fast strategy” to the students without considering the students’ understanding.

Mathematical literacy is a person's ability to formulate, apply, and interpret mathematics in everyday life. This descriptive qualitative research aims to describe the mathematical literacy of 9th grade students in solving Covid-19 context problems. Four students were selected using purposive sampling techniques based on high and middle mathematical abilities. Data collection is done through math literacy tests and interviews. Research shows that students with high math skills can fulfill the mathematical literacy indicators of the stage of formulating, applying, and interpreting, with the correct answers. Middle math ability students can only fulfill the mathematical literacy indicators of the formulating stage and have not been able to answer correctly. High and middle mathematical ability students have very good abilities in formulating a problem. High mathematical ability students have excellent abilities in applying their knowledge to solve problems, while middle mathematical ability students have less ability to apply their knowledge. High mathematical ability students have sufficient ability to interpret the results obtained, while middle mathematical ability students have less ability to interpret the results obtained. High math ability students can use the information about Covid-19 provided to solve problems in the real world. Middle math ability students have not been able to use the information about Covid-19 provided to solve problems in the real world. Teachers need to provide math literacy problems on a regular basis to train students in solving everyday problems.

Mathematical communication skills are the ability to convey mathematical ideas, strategies, and solutions to solve mathematical problems, both written and verbal. The community must express ideas to solve mathematical problems in daily life or tell essential information, such as the news related to COVID-19. . The selection of subjects in this study used purposive sampling with the subjects of 3 high achievement students in ten grade. Subjects are selected based on the average daily test scores. Data collection was conducted by mathematical communication test using PISA liked problem uncertainty and data context about hand sanitizer and interview. The triangulation technique analyzed the result of test and interview data. The results showed that students with high achievement have high mathematical communication skills. Students with high achievement can present mathematical ideas orally and in writing, interpret and evaluate the strategy, the results obtained, and use terms, mathematical notation, and math symbols. Thus, high achievement students can communicate and solve problems in the context of COVID-19. This research provides new information about the mathematical communication of students with high mathematical abilities, so it can be one of the teacher's guidelines for determining appropriate learning to improve students' mathematical communication.