In this paper, we proposed an Electric Circuit manipulation method to identify easily results of Digital Logic Circuits. Using this method for computer science educations, we can feasibly instruct and understand principles of a Digital Logic Circuit which is a basis of real Digital systems. Furthermore, we developed an PBL-based education program for Digital Logic Circuit concept and Boolean Algebra concept by applying the proposed Electric Circuit manipulation method and by explaining real life Digital Instrument examples. The experimental results are analyzed in views of the problem-solving ability and suitability of allocating degrees of difficulties to the developed Digital Logic Circuit problems.