<![CDATA[The implementation of Kurikulum Merdeka in the school isn't realising maximally. There is an obstacle in the execution. That is the learners have the difficulties in learning process that influence to their learning outcomes. It is influenced by a factor, that is the diversity of learners' initial ability, so that the teachers have a role to make learning design that can fulfill all those diversities. The using of learning media also have a role in the successful of the learning. Because of that reason, this research is aim to improve learning outcome of mathematics subjects of 1st class by using Teaching at the Right Level (TaRL) approach and concrete object for length measurement lesson material. This kind of research is classroom action research. The subject of this research is the learners in 1st A class which contain 27 learners, consist of 15 male learners and 12 female learners. The design of this research uses spiral cycle by Kemmis and Mc. Taggart. It is begun with planning, action, observation, and reflection. The technique of data analysis is by descriptive qualitative and the submitting of data is by formative assessment quiz. This research outcome can increase learners outcomes too. It is proved by the increasing of average value of cycle I, that 8,5 (X̅ = 74,1) from pra cycle, that is 65,6 with 74,1% percentage of passing grade learning. The passing grade learning in cycle I is increase about 11,1 % from pra cycle, that is 63%. The average value in cycle II is increase to 80,7 with 88,9% from 27 learners which raise KKM (Minimum Passed Criteria) in 75 ≥ KKM. In cycle II, the learners have raised successful indicator, that is more than 75% learners raise the KKM.]]>
