Almost all countries pay full attention to the education system, especially countries with smaller populations have an advantage in this field. Relatively small countries and regions, including Hong Kong, Singapore, South Korea, Taiwan, Estonia and Finland, were at the top of the results of the 2015 Program for International Student Assessment (PISA) test. This test was carried out by evaluating academic achievement for 15 years around the world. In the last evaluation, Shanghai took the overall top position. Japan is one country that has a good learning concept, with the 4th to 7th positions in various fields of competition. The application of cooperative learning with the development of learning methods is very important to improve the achievement of student learning outcomes. The purpose of this study is to observe the understanding of concepts, and how to think critically in analyzing exam questions. Cooperative learning application with a combination of the "Network Tree Concept Map" method as a depiction to increase students' interest and thinking power.

The learning process involves three important components, namely subject matter, learning activities and assessment (evaluation). Planning each learning scenario needs to always keep in mind the nature of the material to be studied by students, student readiness factors, and student motivation to learn, because what students will learn must be aware of the meaning and benefits for students and for their future lives. Efforts to raise the motivation of class XI students of SMA Negeri 1 Natar South Lampung in learning mathematics have been carried out by teachers in their field of study in various ways, such as providing opportunities for students to ask questions, and designing learning in the form of group discussions. Based on the fact that t arithmetic is between t < t with a significant level of 5%, the value of t = 0.98 < t = 1.76 so that Ho is accepted, the study shows that the average ability of students in the initial test of ability to learn mathematics has increased.

Urban development to big cities generally will be accompanied by excessive use of artificial light, such as street lamps, billboards, and building lighting systems. Ineffective and incorrect lighting installation design causes environmental degradation, i.e light pollution. Today, light pollution is one indicator of environmental degradation and energy waste behavior. Study on light pollution has progressed in many fields of science, extending from traditional fields of astronomy to atmospheric physics, environmental science, natural science, and social life. Measurement of sky brightness is also an indicator of the feasibility of an observatory development plan. The location of the observatory is located at coordinates latitude -05° 27′ 71″ and longitude 105° 09′ 39″ with a height of 1030 above mean sea level. The construction of an observatory requires a study of the sky’s brightness conditions as a matter of consideration to obtain the best observation result. Therefore, to support the Lampung Provincial Government, Institut Teknologi Sumatera (ITERA) and Institut Teknologi Bandung (ITB) in carrying out the construction of observatories in TAHURA WAR, Gunung Betung, Lampung. We did the sky brightness measurements as far as 15 km from the location point of the observatory. We use SQM to measure the brightness of the sky towards the zenith in every crowded area in the city of Bandar Lampung. Then, from the measurement results, we make a map of light pollution. From the mapping results, there are four locations that are indicated to be contaminated by light pollution, namely Tanjung Senang, Teluk Betung, Kemiling, and Gedong Tataan with respective values of 15.8 mpas, 16.6 mpas, 16.8 mpas, and 17.00 mpas.

Penelitian ini bertujuan untuk mengetahui adanya pengaruh penggunaan alat Rabdologia terhadap penguasaan operasi hitung siswa kelas IV semester ganjil SDN 1 Kupang Teba Bandar Lampung. Untuk mencapai tujuan penelitian tersebut, penulis menggunakan metode eksperimen kuantitatif, yaitu dengan melakukan eksperimen terhadap siswa yang menggunakan alat Rabdologia dan yang tidak menggunakan alat Rabdologia. Populasinya adalah seluruh siswa kelas IV SDN 1 Kupang Teba Bandar Lampung. Populasi tersebut diambil 2 kelas, yaitu kelas IV A sebanyak 43 siswa dan IV B sebanyak 42 siswa dan pengambilan sampel menggunakan teknik total sampling. Pengumpulan data yang dilakukan pada penguasaan operasi hitung siswa menggunakan tes essay. Dari hasil perhitungan, untuk uji kesamaan dua rata-rata didapat nilai s = 14,08 dan nilai dan thit = 4, 17 untuk α = 5% , t daf = t (0, 975)(83) = 1, 9923. Dengan demikian, ada pengaruh penggunaan alat peraga Rabdologia terhadap operasi hitung siswa. Sedangkan untuk uji perbedaan dua rata-rata didapat nilai t hit = 4, 17 dan t daf  =  t (0, 95)(83) =1, 6662. Sehingga dapat disimpulkan bahwa rata-rata hasil belajar matematika siswa pada pembelajaran dengan menggunakan alat peraga Rabdologia lebih baik daripada rata-rata hasil belajar matematika siswa yang tidak menggunakan alat peraga Rabdologia.