Knowing the g-value of acceleration of gravity is of paramount importance in various analyzes, and there are several ways of obtaining it experimentally. Here, searching for resources that are easy to apply in high school classrooms, the authors opted for the observation of a simple pendulum, performing a series of measurements of the pendulum period and applying them to the equations (appropriately manipulated for this experiment) of this oscillatory movement. The experiment was carried out in four steps: one with a mass of 10 grams and three with a mass of 20 grams; two with ten swings, one with fifteen and one with twenty. As a result, four values of local acceleration were estimated,which were compared, using the theory of errors, with the value made available in the literature. With these data, the feasibility of using this device in the teaching-learning process was verified, given its ease of handling and assembly, its low cost and its negligible error with the value of the literature.