Critical thinking skills are high-level thinking skills that support intellectual curiosity and give birth to answers that are creative and open. The industrial era of the 21st century 4.0 places great emphasis on critical thinking skills that make it easy for students to deal with a variety of problems. This study aims to design teaching materials in the form of student worksheets that contain activities in accordance with the steps of the problem-based learning model and indicators of critical thinking skills with the ultimate goal of increasing critical thinking skills. This study uses the ADDIE development method with five stages, namely: (1) Analysis, (2) Design, (3) Development, (4) implementation and (5) evaluation. The limit of this research is to analyze and design, the subjects in this study were students of class VII IT Luqman Al-Hakim International Yogyakarta. Data collection instruments include observation sheets, interview guidelines, and validation sheets. The results of the study concluded that the PBL-based student worksheets design to improve critical thinking skills was developed through the ADDIE development method with components: cover pages, preface, table of contents, concept maps, Core Competencies, basic competencies, basic indicators, student worksheets activities, evaluations, and summaries. Student worksheet has been validated by two validators and is categorized as feasible with some revisions that researchers have fixed. This research can be continued at the development and implementation stages.

Abstrack. The purpose of this research is to describe the pointing gesture and teacher's speech SMPN 2 and SMPN 4 Ternate in learning mathematics accordingto information, initiation and feedback. Pointing gesture forms an integrated system with assertive and directive speech and contributes to mathematics learning. Information as an explanation in the conversation and example. Initiation in classroom conversation is a form of opening speech as a trigger/stimulus performed by the teacher with the aim of obtaining student responses. Feedback is teacher's comment on student response. The type of research is case study. In this research, case studies aimed at pointing gestureaccompanied by teacher's assertive speech in information, pointing gestureaccompanied by teacher's directive speech in initiation and pointing gesture accompanied by teacher's assertive in feedback. The result of this research are (1) pointing gesture accompanied by teacher's assertive speechin information, that is teacher giving explanation to student about concept or idea of mathematics in exchange structure of conversation of learning mathematics specially information, (2) pointing gesture accompanied by teacher's directive speech in initiation, that is the teacher asks the students questions about the concept or idea of mathematics in the structure of the exchange of conversation learning mathematics especially initiation and (3) pointing gesture accompanied by teacher's assertive speech in feedback, the teacher explains/elaborates concepts or mathematical ideas and affirming or justifies student answers.

This study aims to describe the mathematical logical thinking ability of students of SMP Negeri 1 Ternate on systems of linear equations in two variables materials. This research uses a qualitative research. Subject of this study were three students of class VIII-J SMP Negeri 1 Ternate.  The data collection stage was conducting tests, categorizing students according to the KBLM level based on the test results, and conducting interviews with research subjects. The data analysis used in this study was to analyze the data from the test results and interviews. The results showed that students at KBLM Level 2 were able to say and write down what was known and what was asked about the questions correctly, were able to use the steps to solve systems of linear equations in two variables and these steps were correct, were able to provide arguments about all steps-steps to solve systems of linear equations in two variables, and be able to draw conclusions correctly on the final answer. Students at KBLM Level 2 were able to say and write down what was known and not write down what is asked, able to use the steps to solve systems of linear equations in two variables and these steps are correct, able to provide arguments about all steps to solve systems of linear equations in two variables, and able to draw conclusions correctly on the final answer. Students at KBLM Level 2 were able to say and write down what was known and not write down what is asked, can use the steps to solve systems of linear equations in two variables but make calculation errors in these steps, do not provide arguments about all the steps solve systems of linear equations in two variables, and do not draw conclusions correctly on the final answer

The aim of this study is to describe the writing gestures accompanied by directive and assertive speech of the teacher in the conversation exchange structure of mathematical learning. Data collection is done by recording and interviewing the teacher. The description of writing gesture along with the teacher's directive and assertive speech is obtained from the results of the recording during class learning and interviews. This case study investigates the writing gesture accompanied by teacher's speech in the conversation exchange structure of mathematical learning. The results of the study show that teachers use writing gestures along with explanations to focus attention and help students understand mathematical material in the information stage. At the initiation stage, the teacher asks questions to obtain students' responses. In the response phase, students respond verbally to the teacher's questions. This verbal response occurs because students have already understood the material asked by the teacher. At the feedback stage, the teacher justifies or confirms the student's verbal response or response by writing down the students' answers or verbal responses on the board. At the initiation stage, the teacher asks questions to students to obtain student responses. In the response phase, students respond verbally to the teacher's questions. This verbal response occurs because students have already understood the material asked by the teacher. At the feedback stage, the teacher uses writing gesture accompanied by the act of confirming or affirming and describing student answers on the board to focus students' attention and help students understand mathematical material.