Tujuan penelitian ini adalah untuk mengetahui Seberapa besar pengaruh aktivitas siswa pada penerapan model Number Head Together berbantu media blok pecahan terhadap hasil belajar matematika siswa kelas IV SDN Gerlang Kecamatan Blado. Penelitian ini adalah penelitian kuantitatif dengan menggunakan desain penelitian Pre-Experimental Design dengan bentuk one group pretest-posttest design. Teknik analisis data menggunakan uji normalitas, t-test dan uji regresi linier sederhana. Hasil analisis uji-t diperoleh t_hitung= 14,99. Kemudian dibandingkan dengan harga t_tabel pada db = 34 dan taraf α = 0,05 adalah 2,045. Sehingga hasil perhitungan diketahui t_hitung>t_tabel, sehingga H₀ ditolak dan H₁ diterima, artinya ada perbedaan rata-rata hasil belajar Pretest dan Posttest. Rata-rata hasil belajar Posttest = 80,00 lebih besar daripada rata-rata hasil belajar Pretest= 55,20. Berdasarkan hasil uji regresi linier sederhana menunjukan pengaruh aktivitas siswa pada penerapan model Number Head Together berbantu media blok pecahan sebesar  R ² = 77,28%. Kesimpulanya yaitu terdapat pengaruh aktivitas siswa dalam penerapan model Number Head Together berbantu media blok pecahan terhadap hasil belajar Matematika siswa kelas IV SDN Gerlang Kecamatan Blado.

Kata kunci: Aktifitas, model Number Head Together, media blok pecahan, hasil belajar.

Abstract: The purpose of this research is to find out how big is the influence of student activity on the application of number Head Together model assisted with media fractional blocks towards the results of learning mathematics grade IV students of SDN Gerlang Blado District. This research is a quantitative research using Pre-Experimental Design research design with one group pretest-posttest design. The data analysis techniques used are normality test, t-test and simple linear regression test. The result of t-test analysis obtained t count = 14,99. Then compared with the ttable price at db = 34 and the level of α = 0.05 is 2.045. So the calculation result is tcount> ttable, therefore H0 is rejected and H1 is accepted, it means there is a difference of average of learning result of Pretest and Posttest. Average learning outcomes Posttest = 80.00 greater than average Pretest learning outcomes = 55.20. Based on the results of simple linear regression test showed the influence of student activity on the application off number Head Together model assisted with media block of fraction R² = 77, 28%. The conclusion is that there is an influence of student activity in the application of number Head Together model assisted with media of fractional block towards the result of learning Math Grade IV student of SDN Gerlang Blado District.

Keywords: Activity, Number Head Together model, fractional block media, learning outcomes