This research aims to figure out: 1) whether the ability of understanding
mathematical concept of the students in the class with Brain Based Learning is better
than the one with Direct Learning; 2) whether self-efficacy of students in the class with
Brain Based Learning is better than the one with Direct Learning. This is a quantitative
experimental research with Post-Test Only Control Design. The population of this
research is all students of grade VII at SMP Negeri 2 Purbalingga. Two classes are
chosen to be the samples of the research using cluster random sampling. Class VIIC is
taught using Brain Based Learning, and Class VIIB is taught using Direct Learning.
The data are analyzed using Independent Sample t-test for post-test and questionnaires
with α = 0,05. It is obtained significant score of the ability of understanding
mathematics concept of 0.008 and self-efficacy of 0.026. Both scores are less than 0.05.
In conclusion, Brain Based Learning is effective towards the ability of understanding
mathematics concept and self-efficacy of the students.