Complex Number Calculator，Complex number arithmetic is used to perform multiplication of two complex numbers. Complex numbers are expressed in the form a+bi where a and b are real numbers. If z=a+bi is a complex number, then a and b are called real and imaginary numbers z, denoted as Im(z) and Im(z) respectively. Complex numbers are used in many scientific fields including engineering, electromagnetism, quantum physics, applied mathematical theory etc. Therefore, it is necessary to learn complex number arithmetic. Complex Number Multiplication Calculator shows the behavior of complex numbers with respect to the basic corresponding multiplication operations of real and imaginary numbers.