This study aimed to determine the effectiveness of Problem Based Learning (PBL)
with MURDER strategy on students mathematical concept understanding ability
in SMP Negeri 2 Sokaraja Academic Year 2018/2019. The method used was
experimental research. Population in the study were the eighth-grade students of
SMP Negeri 2 Sokaraja, totaled to 8 classes. The sampling was done by cluster
random sampling technique; class VIII A as an experimental class treated by
using PBL with MURDER strategy and class VIII B as a class controls that used
conventional learning. That instrument used was a post test problem that
measures the ability to understand mathematical concepts. Based on the result of
the t-test analysis with the help of SPSS 25.0, the Sig (2-tailed) = 0.015. Because
it uses the right-side test, the Sig (2tailed) value is divided by 2 so that it gets
= 0.0075.With α = 0.05 then the value of Sig (2-tailed) meant that Ho rejected.
This meant that the ability of students to understand mathematical concepts who
were exposed by Problem Based Learning (PBL) with MURDER strategy were
more improved from those who only follow conventional learning. Therefore, it
could be concluded that Problem Based Learning (PBL) with MURDER strategy
affected the mathematical concept of understanding ability.