The development of science and technology demands strong mathematical skills in various fields, including technology, science and business. Students who are skilled in creative thinking in mathematics will be better prepared to face challenges in work and everyday life that require data analysis and mathematical problem solving. Mathematics is the foundation for many innovations in the world of technology, science and economics. Purnamasari et al. (2019) [1] Students who think creatively in mathematics have the potential to contribute to the development of science and technology by producing new ideas and solutions that are innovative and useful in solving mathematical problems.

Students are able to use the knowledge and skills they already have to apply them as problem solving in new situations. This relates to the importance of students' prior knowledge according to (Agustami  et al. (2021) [2] stated "prior knowledge referred to the students' previous understanding of the subject content...", meaning that students' prior knowledge refers to the knowledge that students already have before following the learning given. Good initial knowledge can help students easily understand the material to be studied, as well as improve problem-solving abilities.

In solving mathematical problems it is not just about getting a correct solution, but about all possible solutions that can be done, as well as all possible processes and arguments, why the solution makes sense. Hasanah (2021) [3] Solving mathematical problems openly will provide in-depth opportunities for students, so that they can construct all possible solutions to problems creatively, where students' way of thinking in solving a problem is different depending on the knowledge formed in their respective minds, so that diversity can describe the way students' thinking in the learning process, especially in solving problems.

Problem-solving abilities at the high school/MA level are very important because it won't be long before you will enter the campus world or the world of work where creativity and problem-solving abilities are very important. Problem solving is the first step for students in developing ideas and creative thinking skills in building new knowledge based on their initial abilities [4].

The presence of students in the classroom, including when solving mathematical problems, brings knowledge and experience that has been previously obtained. The learning process, including the problem solving process, involves all students' thinking activities, so that the knowledge they have acquired will be connected to new knowledge [5]  Thus, students' initial mathematical abilities are very important, including having an impact on students' problem solving processes.

The research method used is a descriptive qualitative research method with a case study design which aims to describe the mathematical problem solving abilities of class X high school students based on the students' initial mathematics abilities (KAM). The subjects in the research were class X high school students grouped based on KAM, namely high, medium and low ability, 2 people each. Research Instruments The instruments used in this research are: the researcher himself and supporting instruments in the form of initial ability tests, math problem tests, and interview guides. The data collection technique used in this research was by administering an initial ability test, a math problem test, and an interview guide. Data analysis techniques are carried out using the following steps: data reduction, data presentation, data validity, drawing conclusions.

Based on research data analysis, the following results were obtained: Students' Mathematical Problem Solving Ability with High Initial Mathematics Ability where students were able to understand problems well, identify known information and ask questions appropriately. students are able to plan problem solving strategies by choosing appropriate and appropriate methods, students are able to solve problems correctly and systematically, show a strong understanding of trigonometry concepts, students are able to double-check answers and explain mathematical reasoning well. Mathematical Problem Solving Ability of Students with Medium Initial Mathematical Ability where students are able to understand the problem quite well, but there is still a little difficulty in identifying the information being asked, students are able to plan problem solving strategies with guidance, but are still hesitant in choosing the right method, students are able to solve problems correctly, but it takes longer and some steps are inefficient, students are able to recheck answers with guidance, but still have difficulty explaining mathematical reasoning. Suryani et al. (2020) [7] Mathematical Problem Solving Ability of Students with Low Initial Mathematics Ability where students have difficulty understanding the problem, need more detailed explanations to identify information that is known and asked, students have difficulty in planning problem solving strategies, need a lot of guidance to choose the right method, students often make mistakes in solving problems, show a weak understanding of trigonometry concepts, students have difficulty re-checking answers and explaining mathematical reasoning, need a lot of help to understand solutions. The results of the research show that there is a significant relationship between students' initial mathematical abilities and their mathematical problem solving abilities in trigonometry material. Students with high initial mathematics abilities show better problem solving abilities compared to students with medium and low initial mathematics abilities. This shows that initial mathematics skills are an important foundation for students in understanding trigonometry concepts and solving related mathematical problems. Students with strong initial mathematical abilities find it easier to understand the information provided, choose the right strategy, and solve problems systematically.

Initial mathematics ability is an important factor that influences students' mathematical problem solving abilities in trigonometry material. Teachers need to provide attention and learning strategies that are appropriate to students' initial mathematical abilities to help them improve their trigonometry learning outcomes

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2. Agustami, Veti Aprida and Anggi Piramita. "Analysis of students' mathematical problem-solving abilities in solving circle material problems." Mathematics Education Study Program Journal (JPMM), vol. 3, no. 1, 2021, pp. 224–231.

3. Hasanah, Fyrda Jamiatul and Ramlah. "Analysis of mathematical problem-solving abilities on the subject of speed, distance and time in view of students' initial abilities." MAJU, vol. 8, no. 2, 2021, pp. 203–213.

4. Anhar, Latifah Nur et al. "Analysis of mathematical problem-solving ability in geometry material based on Polya steps in view of the mathematical representation ability of class VIII students of SMPN 2 Plupuh 2018/2019." Journal of Mathematics and Mathematics Education (JPMM), vol. 3, no. 1, 2019, pp. 515–524.

5. Apriani, Erni et al. "Mathematics problem-solving ability in view from initial mathematics ability and gender differences." Issues in Mathematics Education (IMED), vol. 1, no. 1, 2017, pp. 7–11.

6. Suryani, Mulia et al. "Analysis of students' problem-solving abilities based on initial mathematics ability." Mosharafa: Journal of Mathematics Education, vol. 9, no. 1, 2020, pp. 119–130.