This study was conducted to determine the effects of the "Moodle LMS which was based on authentic learning approach" and "online learning which was based on authentic learning approach environments" on "mathematics achievement" and "online authentic learning self-efficacy" levels of students in a basic mathematics course. In accordance with the purpose of this study, an experimental design with pre-test and post-test control group was used as the research design. Within the framework of the experimental model, two experimental and one control group were formed with random assignments and were included in different learning environments. Two data collection tools (Mathematics Achievement Test and Online Authentic Learning Self-Efficacy Scale) were developed. As a result, it was seen that there was a significant difference between the mathematics achievement test scores and between the online authentic learning self-efficacy scores when the experimental and control groups were tested later. They had all been doing a Basic Mathematics course in three different learning environments. The significant difference within the context of the two variables was in favour of the working group of the study's students who had their education in a blended learning environment (both traditional face to face and online learning) which was based on the authentic learning approach on Moodle LMS.