The development of Augmented Reality technologies has enabled students to learn in an environment that combines learning resources from the real and digital world. This paper integrates three mobile Augmented Reality-based applications into a series of mathematics lessons on probabilities in a junior high school. This paper aims to examine how mobile AR-based learning applications affect students' learning gains through ANCOVA. Moreover, students' attitudes towards the applications are discussed. The participants are 68 junior high school students. The experimental results show that the mobile AR-based applications would be helpful for students' learning gains in the topic of probability. Students' attitude towards the AR applications in this series of lessons was positive. Overall, it was found that mobile AR-based learning applications have positive effects on junior high students learning mathematics.