ANALISIS KEMAMPUAN PENALARAN MATEMATIS SISWA DALAM MENYELESAIKAN SOAL CERITA MATERI BANGUN RUANG DI KELAS V SDN TLEKUNG 02 KOTA BATU

Mathematics is not just a series of numbers and formulas, but is a tool for logical thinking, solving problems, and making the right decisions. Therefore, mathematics education at the Elementary School (SD) level must be designed in such a way as to provide students with a solid and adequate mathematical foundation. The stages carried out in completing reasoning problems on spatial geometry stories are starting with reading carefully to understand the meaning of each sentence in the question wording, identifying the information contained in the question and then sorting out what is needed to complete the problem. The objective to be achieved in this study is to describe students' mathematical reasoning abilities in completing story problems on spatial geometry material for Class V SDN Tlekung 02 Batu City.

This study uses a descriptive qualitative approach because the problems discussed in this study are not related to numbers, but describe and explain the conditions of fifth grade students at SDN Tlekung 02 Batu City who experience obstacles in mathematical abilities when solving story problems with spatial geometry material. In its implementation, researchers conducted observation, interview and documentation activities in obtaining data. Analysis of research data through four stages, namely data collection, data reduction, data display, and drawing conclusions. Checking the validity of the data uses two techniques, namely source triangulation and technique triangulation. Researchers have carried out several systematic stages to determine students' mathematical reasoning abilities in solving story problems on spatial geometry material in fifth grade elementary school.

The results of the study were obtained through observations, interviews and documentation conducted in May 2025 at SDN Tlekung 02 Batu City with the research subjects being 31 fifth grade students, consisting of 11 male students and 20 female students. Story questions as a written test adapted to the fifth grade learning material, the test aims to determine students' mathematical reasoning abilities in writing by paying attention to students' abilities in understanding, analyzing, and solving problems according to predetermined indicators. After a written test was given to all 31 students, the second stage carried out was that the researcher collected and analyzed the data that had been obtained, this analysis was carried out to identify students who met certain criteria based on problem-solving abilities until 6 students were obtained who answered the story problem solving according to the mathematical reasoning indicators.