Department of Mathematics Education, Yogyakarta State University
Abstract
Algebra is one of the most difficult subject felt by most students and this strand is just started given to the students at early junior secondary school. Infact, if we can manage the algebra subject wisely and attractively, it can be predicted that the students’ conceptual understanding algebra would be relatively improved.
A study was conducted to the Year 7 students at a Junior Secondary of Laboratory School of UPI. The class was set to learn the linear equation topic by using balance (scales).
Through a weighing activity, the students were able to design linear equation models. They followed a guidelines created by the teacher and researcher. The students were not only able to create linear equation models, but also were able to solve mathematical model of linear equation. By using steps of balance (weighing), finally the students were able to know the weight of a hidden quantity.
A number of teachers were involved in an observation activity which were designed in a lesson study context. Information related to the students’ reaction as well as the teachers’ reaction toward the implementation of creating and designing models of linear equation. The information were analysed qualitatively. The results indicate that introducing the linear equation through the scale (balance) were responded positively by the students. A brief interview with the students indicated that the students fluently could solve linear equation, and find the value of variable which infact as a weight variable. This variable seemed to be the weight of hidden variable as the solution of the linear equation.
Moreover, the students were able to interpret the process of weighing to the form of linear equation, since then the students solved it and found the solution of the problem.
While other teachers as observers at the lesson gave comments that the model teacher had practiced the concept of linear equation by using unusual way of teaching.
Intuitively they solved the linear equation by using step by step of weighing process and determined how much weight of an object. The process of weighing and thinking are parallel to solving a linear equation.
Data of test results regarding the linear equation indicated that the students’ understanding of linear equation improved. The researchers recommend to use the balance (scales) as an alternative to teach the topic of linear equation.
Keywords: Balance, realistic, and lesson study