This article is devoted to the issue of using the mathematical and physical pendulum in the teaching of physics and other subjects from the STEM group. The mathematical pendulum is considered a mathematical abstraction in physics, but in practical school practice it can be realized very easily using a thin thread and a small weight (for example, a fishing sinker or plummet). The movement of a pendulum made in this way can be easily described using simple equations for the period of oscillations that students learn about in high school or even elementary school. In this case, they are students of the seventh and eighth grades, but at the moment it is a voluntary subject. The first task that should be completed is the determination of gravitational acceleration, this task can be easily implemented even in elementary school. While the formulas describing the behavior of a mathematical pendulum work with the weight of the weight and its length, in the case of a physical pendulum, the formulas contain the moment of inertia. In the case of experiments with a physical pendulum, it is easiest for students to implement a task dedicated to determining the moment of inertia of a thin rod. For secondary school students, where more emphasis is placed on subjects from the STEM group, it is appropriate to use the pendulum experiment to verify the validity of the so-called Steiner theorem. Model weights designed to verify this theorem are made by students themselves. One of the methods of making the pendulum was 3D printing. In this case, the pendulum had the shape of a hollow box of the desired shape, and the necessary weight was obtained by filling it with plaster. The last task that the students deal with is determining the error of the indirect measurement of gravitational acceleration. While determining the value of gravitational acceleration is easy even for students in the last year of elementary school, in the case of an error in this measurement, the opposite is true. However, this task is suitable for high school students who participate in competitions such as math or physics olympiad. In conclusion, it can be said that teachers can use very simple equipment to implement a large number of tasks with students and pupils, the topic of which is the pendulum.

Keywords: Pendulum, STEM Education, Physics education.