Analysis of Students’ Mathematical Communication Skills in Eight Grade of Junior high school on Number Patterns

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INTRODUCTION
Humans continue to develop various fields of knowledge to solve life's problems progressively. In the past two years, the advancement of science has been accompanied by the emergence of a pandemic, namely Coronavirus Disease of 2019. This has affected the progress of science, particularly in the field of education. The Indonesian government has been forced to implement online learning activities, leading to several challenges faced by both teachers and students. These challenges include limited access to technological facilities for some students, teachers' inadequate mastery of current technology, and unstable internet connections, resulting in suboptimal learning experiences (Nuryana, 2022).
In the learning process, students are expected to have a good understanding of the subject matter. One of the essential skills students need to acquire is mathematical comprehension, also known as mathematical communication skills. According to a study by Prayitno (2013), this skill encompasses the ability to use mathematical language to understand mathematical symbols, express and interpret mathematical ideas both verbally and in writing, whether in the form of diagrams, tables, graphs, formulas, or

METHOD
The descriptive qualitative methodology was used in this study. This study investigated the conditions and circumstances, and the results are presented in the form of a descriptive research report. The subjects for this study were selected based on the results of a prerequisite test on the Number Patterns topic, specifically the material on Arithmetic Series and Progressions. One student with low mathematical ability, one with moderate mathematical ability, and one with high mathematical ability were chosen. These three students are from eighth graders in SMP Negeri 48 Surabaya.
The research used several testing methods. It began with a prerequisite test to determine the subjects, consisting of six essay questions that covered the Arithmetic Series and Progressions topic. This was followed by a mathematical communication ability test, which included three different types of questions with equivalent difficulty levels. Additionally, interviews were conducted with the students and teachers. The student interviews focused on their understanding of the given questions and their approach to solving them to ensure that the students approached the questions properly. The interviews with the teachers involved gathering their opinions regarding the selected students for the mathematical communication ability test. Documentation was used to collect data and information throughout the research process. This included capturing images of the students' test answer sheets.
The data analysis in this research involved the following steps: 1) Data reduction, where the researcher analyzed the students' responses, starting from those with low mathematical ability, progressing to moderate and high ability. 2) Data presentation involved aligning the test results with the indicators of both the subject matter and mathematical communication ability.
This research used triangulation, time, and sources based on different methods, including the mathematical communication ability test on the Number Patterns topic, direct interviews to assess students' understanding of the questions, and documentation of data collected during the research activities.

RESULT AND DISCUSSION
Data of students' mathematical communication skills were obtained from their answer sheets during the mathematical communication ability test and from the interview results. The subjects were students from SMP Negeri 48 Surabaya, specifically one student with low mathematical skills, one student with moderate mathematical skills, and one student with high mathematical skill. These subjects were selected through testing and interviews with mathematics teachers, and the results are as follows.  After obtaining one subject in each category of high, moderate, and low mathematical communication skill, based on the assessment results and interviews, the following are the findings and discussions: a) Subject S (student with high mathematical communication skills) Subject S was able to answer all the given questions provided by the researcher. Below are the answers provided by subject S for question number 1.

Figure 1. Answers S no 1
It is known that the subject raises indications of skills to express their comprehension through writing mathematical thoughts and ideas in accordance with their own language after completing problem number 1. Researchers can say that subject S raises these indicators because the subject is able to get information properly and correctly as in the problem. During the interview session, Subject S was also able to mention information, what is asked for, and the skills to explain the procedures to solve the problem in detail. However, in the subject S completion section, he did not write a conclusion because he was not used to doing so, therefore he forgot to put the conclusion on the answer sheet.
The subject may be observed on the answer sheet above mentioning information from the offered picture questions such as the pattern of the number sequence, difference, first term, and tribe being asked. During the interview session the subject was also able to explain what information was obtained, what was asked, and was able to explain the sequence of completion that the subject had written. However, the subject has not written a conclusion from the results of the answers.
Then the completion of question number 2 on the subject was able to show indicators of students' skills to express their understanding through pictures, graphs and mathematical tables. The following is the result of the subject's answer to question number 2

Figure 2. Answers S no 2
The researcher can say that subject S show these indicators because the subject was able to understand the pieces of stick referred to in the problem, namely the lines in the square shape image.

Figure 3. Answers S no 3
Furthermore, in question 3, the subject could accurately recall the facts from the story problem. The subject created a number sequence pattern that corresponded to the question and correctly answered the question, which was the number of seats in the building/the number of the nth term. Researchers can state that the subject can show indications of students' skill in creating mathematical models through a problem since the subject understands the problem appropriately and correctly as presented by the subject during the interview.  The subject can mention the information in the problem by writing down a series of numbers, writing down what is asked in the problem, and calculating the solution coherently. Researchers can state that the subject is able to bring up indicators of his skill to express his understanding through writing mathematical ideas and ideas in accordance with his own language because the subject is also able to mention the information contained in the problem and explain the sequence when working on the problem during the interview session. Furthermore, in question 2, subject B accurately identified the information, such as counting each line to count the pieces of stick in the picture. However, the subject is still careless when calculating the completion. Based on the image above, the researcher can conclude that subject B indicates students' skills to articulate their understanding through drawings, graphs, and mathematical tables because the subject accurately mentioned the material in the problem during the interview session. However, when the subject answered the problem, he was not careful in documenting the formula utilized, preventing the researcher from correctly solving the problem.
Subject B was then able to obtain the information in question number 3. However, the subject was unable to compute the problem's completion correctly.

Figure 6. Answer B no 3
Based on the image above, the researcher can conclude that the subject can express his comprehension by writing mathematical thoughts and ideas per his own language. And the subject can produce indicators. Students could make a mathematical model through a problem because the subject wrote down the number sequence pattern of the problem. However, in calculating the completion of subject B, it is less precise so the results obtained by the subject are not quite correct.

c) Subject K (Students with low mathematical communication skills)
In question number 1 subject K could not conclude the information contained in the problem, the subject could not choose the concept correctly so that the subject could not solve the problem properly. The following is a picture of the results of the subject's answers to question number 1.

Figure 7. Answer K no 1
However, during the interview, subject could mention the information obtained by mentioning the first term and the difference between each number. The subject can mention the concept given but the subject cannot apply the concept properly. Then in question number 2 the subject did not write down any information, the subject only wrote down the formula and the stages of completion as shown in the following figure.