The purpose of this study is to describe the improvement of the ability to comprehend the concept of mathematics, teacher's teaching skills in managing mathematics learning and student learning activities using Realistic Mathematic Education model assisted BongPas props. The subjects of this study are class V SD 2 Bae, amounting to 14 people consisting of 6 male students and 8 female students. Data collection techniques used are observation, interview, test and documentation. Data analysis in this classroom action research is quantitative and qualitative data analysis. The results showed the ability of understanding the concept of mathematics in the first cycle is 35.7% with less criteria and the second cycle is 78.5% with good criteria. The result of observation of teacher's teaching skill in managing learning has increased, from cycle I get percentage of 76% with good criterion, while cycle II get 86,5% percentage with very good criterion. The observation of student learning activity has increased, from cycle I with percentage of 71% with good criterion while cycle II with percentage 82% with very good criterion. Based on the research that has been done, it can be concluded that the ability of understanding the concept of mathematics, teaching skills of teachers in managing learning and learning activities of students in grade V SD 2 Bae increased after the implementation of Realistic Mathematic Education model assisted BongPas props.

The purpose of classroom action research is to improve the students mathematic problem solving skills of grade IV SD 1 Kedungdowo through the problem based learning model assisted by lego. This research is a classroom action research with teacher research subject and 28 students. This study lasted for 2 cycles, each cycle consists of 4 stages of planning, action, observation and reflection. The independent variable in this research is lego assisted PBL. While the dependent variable in this research that is problem solving ability. Data collection techniques used is tests, observations, interviews and documentation. Data analysis used is quantitative and qualitative data analysis. The results showed that there was an increase of problem solving ability of mathematics in cycle I and Cycle II, that is from 70,92 (good) to 74,28 (good) with percentage of classical learning completeness equal to 64% to 86%. Supported by an increase in problem solving activity students score 2.51 (good) to 3.01 (good). In addition, teachers' skills in managing mathematics learning also increased by 74% (good) to 85% (very good).

Elementary school teachers should know how their students construct a very abstract concept of mathematical knowledge. Elementary school children are still at the concrete operational stage, while the characteristic of mathematics itself is abstract. This study is descriptive qualitative research. Data collected by observation and documentation. The study describes how Elementary school students should build their mathematical knowledge based on Bruner’s Theory (enactive, iconic and symbolic stage) and how mathematics learning process provided by Elementary school teachers.

Mahasiswa PGSD Universitas Muria Kudus berasal dari berbagai jenis latar belakangjurusan seperti SMA/MA IPA, IPS, Bahasa serta SMK dari berbagai jurusan. Tidaksemua mahasiswa tersebut mempunyai pemahaman yang kuat tentang matematika.Sebagian besar dari mereka yang berasal dari jurusan non eksak mengalami kesulitandalam memahami konsep matematika. Miskonsepsi terjadi paling banyak pada lingkupmateri geometri. Hal ini menjadi tantangan bagi para Dosen eksak untuk mengantarkanmateri-materi matematika agar lebih mudah dipahami oleh semua mahasiswa. Tujuandari penelitian ini adalah untuk melihat bagaimana Inquiry based Learning berbantuanperaga manipulatif dalam meningkatkan pemahaman konsep matematika mahasiswaPGSD Universitas Muria Kudus. Penelitian ini merupakan penelitian tindakan kelasyang dilaksanakan dengan dua siklus dengan urutan tahapan perencanaan, tindakan,pengamatan dan refleksi. Subjek penelitiannya adalah mahasiswa 2G. Datadikumpulkan dengan observasi dan tes. Hasil penelitian menunjukkan bahwa Inquirybased Learning berbantuan peraga manipulatif mampu meningkatkan pemahamankonsep matematika mahasiswa PGSD Universitas Muria Kudus. Peningkatanpemahaman konsep terlihat dari: 1) rata – rata hasil tes meningkat dari 71,33 pada siklus1 menjadi 82,45 pada siklus 2, 2) rata – rata aktivitas pembangunan konsep meningkatdari 2,65 dengan kriteria baik menjadi 3,25 dengan kriteria baik. Dari penelitian ini,dapat disimpulkan bahwa Inquiry Based Learning berbantuan peraga manipulatifmampu meningkatkan kemampuan pemahaman konsep matematika pada materiGeometri pada mahasiswa PGSD, model Inquiry Based Learning berbantu peragamanipulatif dapat juga digunakan untuk pembangunan konsep matematika lingkupmateri lain seperti bilangan, pengukuran, Statistika dan pengolahan data.