The research at XYZ School examines the impact of using the bar model, logical thinking, and concept mastery on the ability to solve mathematics problems in 3rd-grade elementary students. Concept mastery, logical thinking ability, and the application of the bar model are used to measure student capabilities. The study employed a True Experimental Design, with the data collected through the questionnaires from 30 students, pre-tests, and post-tests, and analyzed using validity, reliability, and tendency tests. The analysis results show that the implementation of the bar model method can enhance students' logical thinking skills and concept mastery, which in turn makes it easier to solve mathematics problems. The SEM analysis with smart PLS was used in this study and it was revealed that significant positive correlation between the use of the bar model and concept mastery in word problem mathematics (p-value 0.000, t-statistic 9.388), logical thinking ability (p-value 0.000, t-statistic 8.806), and problem-solving ability (p-value 0.000, t-statistic 4.057), all exceeding the critical value of 1.96. Overall, the results of this study have demonstrated that the use of the bar model has a positive impact on concept mastery, logical thinking ability, and the problem-solving skills of 3rd-grade students at XYZ School, making the bar model an effective tool in improving students' mathematics skills. / Penelitian di Sekolah XYZ mengkaji pengaruh penggunaan bar model, berpikir logis, dan penguasaan konsep terhadap kemampuan memecahkan soal matematika pada siswa Kelas 3 Sekolah Dasar. Penguasaan konsep, kemampuan berpikir logis, dan penerapan bar model digunakan untuk mengukur kemampuan siswa. Penelitian menggunakan True Experimental Design dimana data dikumpulkan melalui kuesioner dari 30 siswa, pre-test, dan post-test, serta diuji melalui uji validitas, reliabilitas, dan kecenderungan. Hasil analisis menunjukkan bahwa penerapan metode bar model dapat meningkatkan kemampuan berpikir logis dan penguasaan konsep siswa, yang pada gilirannya mempermudah penyelesaian masalah matematika. Penelitian ini menggunakan analisis SEM dengan SmartPLS, dan menemukan korelasi positif yang signifikan antara penggunaan bar model dengan penguasaan konsep soal cerita matematika (p-value 0,000, t-statistic 9,388), kemampuan berpikir logis (p-value 0,000, t-statistic 8,806), serta kemampuan memecahkan masalah (p-value 0,000, t-statistic 4,057), semuanya melebihi nilai kritis 1,96. Secara keseluruhan, hasil penelitian ini membuktikan bahwa penggunaan bar model berpengaruh positif terhadap penguasaan konsep, kemampuan berpikir logis, dan kemampuan siswa Kelas 3 SD XYZ dalam memecahkan masalah matematika, sehingga penggunaan bar model efektif dalam meningkatkan keterampilan matematika siswa.