Abstract:
The crabs are organisms that have a major role in the mangrove ecosystem. The preservation of the
mangrove ecosystem cannot be separated from the roles and responsibilities of humans. This can be
started by creating awareness and practicing thinking skills to provide solutions to various existing
environmental problems. According to the results of the TIMSS study, the low scientific ability of
Indonesian students, especially its implementation in the form of scientific literacy, has not shown a
good improvement so that learning innovations are needed, one of which is the manufacture of
environment-based teaching materials. The purpose of this study was to describe the practicality of
the teaching materials "Crab Types in the Mangroves Area" in training students' critical thinking skills
at MAN Tanah Laut. The type of research used is the Tessmer formative test. The research data were
analyzed descriptively, practical data included the feasibility of using teaching material and student
responses, indicating that the teaching materials developed were practical for use in learning and
could improve the critical thinking skills of MA students.
Keyword: Practicality, Teaching Materials, Crab, Mangrove, Critical Thinking Skills
