This research aims to remediate students\u27 errors in solving ideal gas problems using Learning Together method assisted by Student Worksheet among students in Junior High School 1 Sekayam. Pre-experimental desing was choosen as the method in this research, using intact group method, 28 students from class XI IPA 2 academic year 2013/2014 was chosen to participate in the one group pretest-posttest design. McNemar and Chi Quadrat test showed that there was a significant decline in the number of students who experience mathematical errors (36,42%), physics errors (31,42%) and conception errors (21,42%). It is sugested for further study to conduct an alternative remediation activity in order to improve these results