<p>This research is aimed to identify students’ misconceptions in proving onto and one-to-one function in Abstract Algebra using CRI (Certainty Response Index), which is an instrument to distinguish misconceptions and errors. This research uses qualitative method. There are eighteen research participants, and they are Mathematics Education students in 3rd semester. Researcher asked participants to solve some problems related to mathematical proof. Then, participants gave score based on their belief or level of certainty. The result shows that ten students get misconceptions. They were weak in understanding the definition of onto and one-to-one function, and are not yet trained to proof onto and one-to-one function in Abstract Algebra. Further, this research also find that the errors of participants in proving mathematics are mainly influenced by errors in algebraic operation.</p>

This study aims to classify student responses in dealing with probabilistic problems according totheir level, analyze, and identify indicators at each level. This study used a descriptivequalitativeapproach with data collection techniques in the form of tests and interviews which were tested on 66 seventh grade students as research subjects. The results showed that 28 students were at the subjective level, 30 students were at the transitional level, and 8 students were at the informal quantitative level, and no students were at the numerical level. In addition, there are additional indicators at the subjective and transitional levels. Meanwhile, at the informal quantitative level, there are no additional indicators.Keywords: probabilistic thinking

Penelitian ini bertujuan untuk mendeskripsikan eksplorasi pola barisan bilangan aritmatika pada ketukan irama gending lancaran dalam kesenian alat musik gamelan Tembung Dolanan studi kasus pada Gending Gugur Gunung. Jenis penelitian ini kualitatif dengan pendekatan etnografi. Data yang disajikan dalam penelitian merupakan hasil dari wawancara, observasi, dan dokumentasi. Hasil penelitian menunjukkan bahwa pada Gending Lancaran yang dimainkan dengan alat musik gamelan memiliki suatu konsep matematika yaitu pola barisan aritmetika yang terdapat di setiap ketukan pada Tembung Dolanan. Hasil penelitian menunjukkan bahwa dalam ketukan nada yang dipukul dengan alat musik Kethuk, Kempul, Kenong, dan Bonang Babok memuat pola barisan aritmatika. Bentuk umum pola barisan aritmatika dalam ketukan atau pukulan dari alat musik Kethuk yaitu mn= 2n - 1.  Bentuk umum pola barisan aritmatika dalam ketukan atau pukulan alat musik Kempul yaitu mn = 4n + 2. Bentuk umum pola barisan aritmatika dalam ketukan atau pukulan dari alat musik Kenong yaitu mn = 4n. Bentuk umum pola barisan aritmatika dalam ketukan atau pukulan dari alat musik Bonang Babok yaitu mn= 4n.