抄録
Diagrams and slide rules for real numbers are practically used by scholars and engineers every day. These diagrams and slide rules serve speed & easiness in multiplication division and other difficult computations. Now complex numbers are used also in physics and engineering, specially in electric engineering. But the computation of complex numbers are so difficult and trouble some that they often lead many errors & mistakes in calcutation. Then diagrams & slide rules for complex numbers are devised in order to facilitate the computation, and to make it possible to calculate rapidly and to check.
