<![CDATA[ABSTRACT Mathematics learning on plane geometry continues to face challenges in fostering students’ conceptual understanding, as learners are expected not only to obtain correct answers but also to explain the mathematical reasoning underlying their solutions. This study investigated the effectiveness of the Think Pair Share (TPS) learning model supported by question cards in improving the mathematical conceptual understanding of fourth-grade students at MIN 4 Bandar Lampung. A quantitative approach was employed using a quasi-experimental design with a nonequivalent control group design, involving 56 students, comprising 28 students in the experimental group and 28 students in the control group. Data were collected through validated and reliable essay tests and analyzed using the Shapiro–Wilk test, Levene’s test, and an independent samples t-test. The mean pretest scores were 60.46 for the experimental group and 55.29 for the control group. Following the intervention, the mean posttest score increased to 81.18 in the experimental group, whereas the control group achieved a mean score of 65.71. The analysis revealed a significance value of p < 0.001, indicating a statistically significant difference in students’ conceptual understanding between the two groups. These findings suggest that integrating the TPS model with question cards provides an effective instructional strategy for strengthening elementary students’ mathematical conceptual understanding by promoting individual thinking, collaborative discussion, and meaningful knowledge construction. ABSTRAK Pembelajaran matematika pada materi bangun datar masih menghadapi tantangan dalam membangun pemahaman konsep yang utuh sehingga peserta didik tidak hanya mampu memperoleh jawaban, tetapi juga menjelaskan alasan matematis yang mendasarinya. Kondisi tersebut mendorong pengujian efektivitas model Think Pair Share (TPS) berbantuan media kartu soal terhadap pemahaman konsep matematika peserta didik kelas IV MIN 4 Bandar Lampung. Penelitian menerapkan pendekatan kuantitatif dengan rancangan quasi-experimental tipe nonequivalent control group design yang melibatkan 56 peserta didik, terdiri atas 28 peserta didik pada kelas eksperimen dan 28 peserta didik pada kelas kontrol. Data diperoleh melalui tes uraian yang telah memenuhi persyaratan validitas dan reliabilitas, kemudian dianalisis menggunakan uji Shapiro–Wilk, uji Levene, dan independent samples t-test. Rata-rata pretest kelas eksperimen sebesar 60,46 dan kelas kontrol 55,29. Setelah perlakuan, rata-rata posttest meningkat menjadi 81,18 pada kelas eksperimen, sedangkan kelas kontrol mencapai 65,71. Hasil pengujian menunjukkan nilai signifikansi p < 0,001 yang mengindikasikan adanya perbedaan kemampuan pemahaman konsep secara signifikan antara kedua kelompok. Temuan ini memperlihatkan bahwa integrasi TPS dan media kartu soal merupakan strategi pembelajaran yang efektif untuk memperkuat pemahaman konsep matematika peserta didik sekolah dasar melalui keterlibatan berpikir, berdiskusi, dan mengonstruksi gagasan secara lebih bermakna.]]>
