Penelitian ini bertujuan untuk mengetahui pengaruh model pembelajaran kooperatif tipe Numbered Heads Together (NHT) terhadap kemampuan pemecahan masalah matematika siswa kelas XI IIS Madrasah Aliyah Negeri Tarakan. Penelitian ini dilaksanakan dilaksanakan pada semester ganjil tahun pelajaran 2017/2018 di Madrasah Aliyah Negeri Tarakan.
Jenis penelitian ini adalah quasi exsperimental research dengan desain posttest only control design. Populasi dalam penelitian ini adalah seluruh kelas XI IIS Madrasah Aliyah Negeri Tarakan. Sampel penelitian ini adalah kelas XI IIS-1 sebagai kelas eksperimen dan XI IIS-2 sebagai kelas kontrol, Sampel penelitian diambil dengan teknik sampling jenuh. Teknik pengumpulan data dalam penelitian ini menggunakan tes. Data dianalisis menggunakan analisis statistik dengan bantuan software SPSS versi 23.0 for windows.
Hasil analisis deskriptif menunjukkan bahwa skor rata-rata kemampuan pemecahan masalah matematika siswa kelas eksperimen adalah 66,65 dan skor rata-rata kemampuan pemecahan masalah matematika siswa kelas kontrol adalah 58,50 Sedangkan berdasarkan hasil analisis uji independent sample t-test dengan taraf signifikan 5% (? = 0,05) diperoleh nilai signifikan (1-tailed) sebesar 0,0025. Sehingga dapat dilihat bahwa 0,0025 < 0,05. Dengan demikian Ho ditolak dan Ha diterima, sehingga dapat disimpulkan bahwa model pembelajaran kooperatif tipe Numbered Heads Together (NHT) berpengaruh terhadap kemampuan pemecahan masalah matematika siswa.

Kata Kunci: Model Pembelajaran Kooperatif Tipe Numbered Heads Together (NHT), Pemecahan Masalah

The objective of this research was to find out the effect of Numbered Heads Together (NHT) type cooperative learning model on mathematical problem solving abilities of IIS XI grade students of Madrasah Aliyah Negeri Tarakan. This research was conducted in the odd semester of 2017/2018 academic year at Madrasah Aliyah Negeri Tarakan. The type of this research is quasi experimental research with posttest only control design. The population of this research was all students in class XI IIS Madrasah Aliyah Negeri Tarakan. The sample of this research was class XI IIS-1 as the experimental class and XI IIS-2 as the control class. The sample was taken with saturated sampling technique. The technique of data collection used by the researcher was tests. The data were analyzed by using statistical analysis by using of SPSS version 23.0 for Windows software. The descriptive analysis showed that the mean score of students’ mathematical problem solving abilities in experiment class was 66,65 and the mean score of students’ mathematical problem solving abilities in control class was 58,50. Whereas based on the analysis results of independent sample t-test with a significant level of 5% (? = 0.05) a significant (1-tailed) value of 0,0025 was obtained. So it can be seen that 0,0025 < 0.05. Thus Ho is rejected and Ha is accepted, so it can be concluded that the Numbered Heads Together (NHT) type of cooperative learning model influences students' mathematical problem solving abilities. Keywords: Numbered Heads Together (NHT) Type Cooperative Learning Model, Problem Solving