The concept is a strength for students in learning mathematics and understanding the concept is one very important aspect in learning mathematics. Understanding the concept in this study is when students can translate, interpret and conclude a mathematical concept based on his own knowledge, not just knowledge of memorization. By understanding the concept, students can develop their abilities in learning mathematics. Students can also apply learned concepts to solve simple problems to complex problems. In addition, the level of depth of understanding of a concept can also determine the level of mathematical ability in students, including the concept of algebra. Algebra is an important concept because it is one of the basic concepts in high school math learning. However, the reality of the field found the findings that students' concept of understanding the concept of algebra is still low. This condition is indicated by data of daily mathematical test result 5 times followed by 30 students, the result shows that average only 21.25% of all students are able to reach Minimum Criterion Completion (KKM). Another result of the pre-research that researchers conducted on 25 SMPN students in Bangkalan, only 4 students were able to answer correctly about the understanding of algebra material given, this can indicate that the students' knowledge of algebra material is still low.

 

This study aims to determine the understanding of the concept of Algebra’s SMP students in terms of differences in mathematical ability. The method used is descriptive qualitative where the data obtained in the form of words written or oral from the subject. Data collection used mathematical ability tests and algebraic understanding tests to investigate students' understanding of algebraic concepts and interviews. Some of the indicators studied in this study include: (1) the ability to re-concept, (2) the ability to present concepts in various forms of mathematical representation, and (3) the ability to link concepts. The subjects of this study are the students of grade VIII SMPN in Madura who have high, medium and low mathematics skills. Here is a table of indicators understanding the concept of algebra according to the level of mathematical ability.

 

Indicator

 

Subjet

The ability to re-concept

The ability to present concepts in various forms of mathematical representation

The ability to link concepts

High

ü

ü

ü

Medium

ü

 

ü

Low

 

 

ü

 

The results show that high-ability students can provide algebraic understanding of their own language and can provide examples. In addition, high ability students can provide understanding of variables, constants and coefficients by mentioning examples. High-ability students can name examples of similar and unlike tribes. High-ability students can solve problems using concepts attributed in everyday life. Moderate students are able to provide understanding of algebraic forms according to their own language and can provide examples. Moderate students are able to provide understanding of variables, constants, coefficients and can cite examples. Moderate students are able to name examples of similar tribes and unlike. Students with moderate ability can not solve the problem using the concept associated in daily life because they feel confused and less understood what would be associated with in everyday life. The low-ability student can not give an understanding of the algebraic form because it forgets the notion of algebraic form, the low-ability student can not give the definition of variables, constants, coefficients with the example. However, low-ability students are able to name similar tribes and are not the same as examples. Subjects are able to solve problems using the concepts associated in daily life.

 

Based on the analysis of the three subjects above, it can be concluded that high-ability and moderate subjects can give an understanding of algebraic forms, variables, constants, coefficients with examples. In the subject of high and low ability can mention examples of similar tribes and not similar and can solve the problem using the concept associated in daily life. While on the subject of low-ability can mention examples of similar tribes and not similar. On the subject of ability is not able to solve the problem using the concept associated in everyday life. In low-ability susbjects can not give understanding of algebraic forms, variables, constants, coefficients with examples.

Conclusion, based on the results of the study, students of high and moderate ability to understand in re-proclaim the concept, linking the concept in everyday life while in the low ability students there is still difficulty in re-concept and link the concept in everyday life.