This paper introduces a safe, interesting, convenient, and low-cost experiment. The products of galvanic cells and electrolytic cells are compressed into specimens that are placed on a slide to stretch the metal dendrites in one plane and ensure they are not easily destroyed by external factors. The details and growth process of the metal dendrites can be clearly observed with the naked eye and optical microscopy, which arouses interest from students and allows them to enjoy the beautiful images while obtaining a large amount of macroscopic information. By allowing the students to observe the macroscopic phenomena and the corresponding microscopic changes among the microparticles, it is possible for them to explain the morphological origins and growth rates of the metal dendrites, which deepens their understanding of the reactions that occur in galvanic and electrolytic cells.