<![CDATA[This study was motivated by the low mathematics learning outcomes of fifth-grade students at SD Negeri 101818 Pancur Batu, caused by conventional teacher-centered instruction and limited utilization of interactive media. This study aims to determine students' mathematics learning outcomes before and after the implementation of the Numbered Heads Together (NHT) learning model assisted by Quizizz media, as well as to examine its significant effect on students' achievement. The research method used was an experimental method employing a pre-experimental one-group pretest-posttest design. The population as well as the sample consisted of all 36 fifth-grade students selected through a purposive sampling technique. Data were collected using an achievement test consisting of 25 validated multiple-choice items. The results showed that the mean pretest score of 60.66 increased significantly to 83.11 on the posttest. The Kolmogorov-Smirnov normality test indicated that the data were normally distributed, and hypothesis testing using a paired sample t-test yielded t_"calculated" =14.353≥t_"table" =2.030 at a significance level of α=0.05. Consequently, it can be concluded that the implementation of the Numbered Heads Together learning model assisted by Quizizz media exerts a positive and significant effect on the mathematics learning outcomes of primary school students. ABSTRAK Penelitian ini dilatarbelakangi oleh rendahnya hasil belajar matematika siswa kelas V SD Negeri 101818 Pancur Batu yang disebabkan oleh pembelajaran konvensional dan minimnya variasi media interaktif. Penelitian ini bertujuan untuk mengetahui hasil belajar matematika siswa sebelum dan sesudah diterapkan model pembelajaran Numbered Heads Together (NHT) berbantuan media Quizizz, serta menganalisis signifikansi pengaruh model tersebut terhadap hasil belajar matematika siswa. Metode penelitian yang digunakan adalah metode eksperimen dengan desain pre-experimental design jenis one-group pretest-posttest design. Populasi sekaligus sampel penelitian adalah seluruh siswa kelas V yang berjumlah 36 siswa, yang ditentukan menggunakan teknik purposive sampling. Data dihimpun melalui instrumen tes hasil belajar berbentuk pilihan ganda sebanyak 25 butir soal yang telah teruji validitas dan reliabilitasnya. Hasil penelitian menunjukkan nilai rata-rata pretest sebesar 60,66 meningkat secara signifikan menjadi 83,11 pada posttest. Uji normalitas Kolmogorov-Smirnov menunjukkan data berdistribusi normal, dan pengujian hipotesis menggunakan uji-t berpasangan menghasilkan nilai t_"hitung" =14,353≥t_"tabel" =2,030 pada taraf signifikansi α=0,05. Dengan demikian, dapat disimpulkan bahwa penerapan model pembelajaran Numbered Heads Together berbantuan media Quizizz berpengaruh positif dan signifikan terhadap peningkatan hasil belajar matematika siswa kelas V sekolah dasar. ]]>
