This research aims to improve student learning outcomes on mathematics learning by using a contextual approach. This research is a Class Action Research (CAR) conducted at one of the vocational schools (SMK) in X-class areas of focus on Automation of Governance and Office 3. The research instruments used in this study are (1) tests consisting of pre-test and post-test of the concept of Sigma notation and infinite series; and (2) the use of an observation sheet for teachers and students as a condition of measuring action execution. The procedure of the study consists of (1) planning, (2) The implementation of Action, (3) observation, (4) evaluation, and (5) reflection. The test results showed that there was an increase in pre-test and post-test results of 19.33%. Obviously, this shows that students ' learning outcomes on math learning are increasing after learning using a contextual approach.

SMA/SMK was the last high school before going to College. High school students/CMS are at the stages of adolescent age. The World Health Organization (1974) set the age limit of 10-20 years as a teenage limit (Sarwono,2008). Based on a review of the theory of progression, the age of adolescence is a time of onset of rapid changes, such as physical changes, changes in fundamental aspects of cognitive, emotion, social and achievement. Teens experiencing instability from time to time and they try to adopt new behavior from the previous development phases (Soetjiningsih,2004).  Teens often have problems because of her unstable and still has not been formed in cooked. The attitude of the labile affected the level of confidence, such as the fearless try and there are times when his minder with her own.

Perkembangan teknologi mempengaruhi semua aspek kehidupan, begitupun di dunia pendidikan. Tuntutan guru menjadi lebih banyak, selain administrasi yang harus diselesaikan, ditambah dengan keharusan untuk mampu menggunakan teknologi. Salah satu alternatif solusinya adalah dengan menerapkan pelatihan ASGAR yang bertujuan untuk mendukung kegiatan guru-guru dalam pembelajaran matematika. Metode yang digunakan yaitu berupa workshop dan pelatihan secara langsung menggunakan ASGAR kepada guru mulai dari tingkatan SD, SMP dan SMA yang ada di pangalengan. Hasil pelatihannya yaitu pelatihan ASGAR ini mndapat respon positif dari para guru peserta pelatihan.mengetahui bahwa pembelajaran matematika bisa dilakukan dengan menarik sehingga pembelajaran tidak akan terasa membosankan, dan menggunakan media tersebut dalam penyampaian konsep dari suatu materi dengan efisien dan efektif, mengeksplorasi media tersebut sesuai dengan materi yang ingin disampaikan oleh guru.

The research aims to identify students ' work in resolving the problem of polyhedron. This research used a qualitative descriptive method conducted at the state Junior High School in Batujajar. The instrument used in this research is a test of the problem that has been adjusted to the indicator of the polyhedron material of a) mention the elements of the cube, Cuboids, Prism, and Pyramid (ribs, field, side, diagonal field, diagonal space, field Diagonal); b) determines the surface area of the polyhedron c) The volume of polyhedron; d) solve the problem of polyhedron in daily life. Based on the research results of the 4 problems given are received percentage value in a row of 29.03%; 66.12%; 65.70%; 47.90% of the results showed that students are still struggling in determining the elements of polyhedron chamber and creating a mathematical model of the story related to everyday life.