Based on the results of preliminary studies at grade VIII SMP in the field, it is still found a mathematical problem solving ability of students in real problem who have not optimally and students activities do not support their learning process. One of the factor is unsuitable of learning tools that can be facilitate learners to improve solving of mathematical problems ability and student's activities to learn. From that case, to be underlying to do development learning tools of mathematics, there are plan lesson plan (RPP) and student's worksheet (LKPD) on Problem Based Learning (PBL), which can provide a learning experience to learn problem solving and can provide a good potential effects on student's activities during the learning proccess. Data were collected through observation, questionnaires, interviews, and test problem solving abilities. The subjects of this research are students grade VIII SMP N 3 Sawahlunto. This research development is used Plomp mode consists of phase preliminary research, prototype phase, and assessment phase. Based on the data analysis result, it was showed that the learning equipment based on PBL has fulfilled valid criteria in term of content and construct. The lesson equipment has been considered as practical in terms of implementation and the efficiency of time use by teachers and students. The lesson equipment has also been effective in terms of process the presentation mastery learning students after using the device based learning problem-based learning is greater than or equal to 75% while in terms of results the average student has been active in the learning. Based on these results, it can be concluded that the mathematics lesson equipment based on PBL which was conducted to student's of class VIII was valid, practical, and effective.

Abstract. Learning equipment is important things that determine the quality of the learning process and output. We need a study about validity, practicality, and effectiveness of the learning equipment to ensure teaching and learning quality. The purpose of this research is to evaluate the validity of the learning equipment based on guided discovery, especially the students’ worksheets. This research was a descriptive qualitative research that provides the result of students’ worksheets and experts recommendation. The experts who validated these student’s worksheets were three experts on mathematics education. The instruments used in this study was the validation sheets for LKPD. The result of validation sheets analysis for LKPD showed that in general, the students’ worksheets were valid. The validity of the didactical aspect and contents aspect sequently were 0,667 dan 0,704. Keywords: students’ worksheets, guided discovery, mathematical concepts understanding, mathematical reasoning abilities Abstrak. Perangkat pembelajaran merupakan kelengkapan pelaksanaan proses pembelajaran yang sangat penting dan menentukan capaian proses dan hasil pembelajaran. Untuk menjamin kualitas perangkat pembelajaran, dibutuhkan kajian khusus untuk menilai validitas, praktikalitas dan efektifitas perangkat pembelajaran yang digunakan. Penelitian ini bertujuan untuk menilai aspek validitas perangkat pembelajaran, khususnya Lembar Kerja Peserta Didik (LKPD) berbasis penemuan terbimbing yang digunakan dengan tujuan meningkatkan kemampuan pemahaman konsep dan penalaran matematis siswa. Penelitian ini merupakan penelitian kualitatif deskriptif yang menyajikan data hasil validasi dan saran validator terhadap validitas LKPD berbasis penemuan terbimbing. Validator terdiri dari tiga orang pakar pendidikan Matematika. Instrumen yang digunakan adalah lembar validasi LKPD. Hasil analisis terhadap lembar validasi menunjukkan bahwa secara umum LKPD memenuhi kriteria valid. Validitas aspek didaktik dan aspek isi berturut-turut adalah 0,667 dan 0,704. Kata Kunci: validitas lembar kerja peserta didik,  penemuan terbimbing, pemahaman konsep matematis, kemampuan penalaran matematis

Abstrak. Berdasarkan hasil penelitian pendahuluan, kemampuan pemecahan masalah matematika di kalangan siswa kelas XI SMA di lapangan belum dikembangkan secara optimal dan proses pembelajaran juga tidak mendukung aktivitas siswa untuk secara aktif mempromosikan pengetahuan. Salah satu alasannya adalah tidak tersedianya perangkat pembelajaran yang dapat mendukung peningkatan pemecahan masalah dan aktivitas siswa di SMA kelas XI. Ini adalah tujuan mendasar dari pengembangan perangkat pembelajaran matematika seperti rencana pelajaran dan lembar kerja siswa berdasarkan penemuan terpandu dalam materi statistik untuk meningkatkan kemampuan pemecahan masalah matematika dan aktivitas siswa. Jenis penelitian ini adalah penelitian pengembangan dengan menggunakan model Plomp yang terdiri dari tiga tahap yaitu penelitian pendahuluan, tahap pengembangan prototipe dan tahap penilaian. Subjek penelitian adalah siswa kelas XI SMA N 7 Padang. Data dikumpulkan melalui observasi, dokumentasi, kuesioner, wawancara dan tes. Berdasarkan hasil validitas data analisis menunjukkan bahwa alat pembelajaran berdasarkan penemuan terpandu yang telah memenuhi kriteria valid dalam hal isi dan konstruk kemudian diuji pada siswa kelas XI SMA N 7 Padang. Perangkat pembelajaran sudah praktis dalam hal kemudahan penggunaan karena bisa diterapkan dalam kegiatan belajar. Selain itu, tahap penilaian dilakukan uji efektivitas bertujuan untuk melihat hasil kegiatan pembelajaran berupa kemampuan memecahkan masalah siswa setelah

The main focus of the study was to identify the the effects of the ACE teaching cycle approach on students' engagement in learning of Elementary Linear Algebra. The Elementary Linear Algebra course was delivered at the Mathematics Education Study Program of State University of Padang, Indonesia. An action research methodology was adopted for the study and the constructivist theory was used as a theoretical framework. This study used mixed methods to collect, describe, and interpret the data. The data were collected through focus group discussion, classroom observations, and questionnaire. The participants in this study consisted of 37 students enrolled in the Elementary Linear Algebra course during the January-June 2011 semester. The ACE teaching cycle approach that was implemented in this study consisted of three steps. The first step in this cycle was the concept maps activity. This activity encouraged students to prepare for the topics that would be discussed in the class. The next step was classroom discussion which provided a social context in which the students could work together to solve mathematics problems. Finally, exercises were assigned as homework. In this part, students practised solving mathematics problems and wrote reflective journal. Students' involvement in the ACE teaching cycle approach in the Elementary Linear Algebra course improved their engagement in mathematics learning in the three domains of cognitive engagement, affective engagement and behavioural engagement.

Student engagement is important in every learning because learning activities are not just a transfer of knowledge but also as a potential development that is owned by students. This study aims to determine the increase student’s engagement of MTs grade VIII learn based contextual teaching and learning (CTL) learning device in the form of lesson plans and student worksheets. The research design used One Group Design. The sample of this study involved students of class VIII in the 2018/2019 school year were 25 students of class VIII.1 as an experimental class. The instrument used was a student engagement questionnaire and field notes. Data were analyzed quantitatively using means and n-gain and described descriptively. The results showed that the n-gain was 0.215, which means that there was an increase in the student’s engagement learning by using CTL-based mathematics learning in the low category.