In this paper, a new SN P system is investigated in order to compute the product of any two decimal natural numbers. Firstly, an SN P system with two input neurons is constructed, which can be used to compute the product of any two binary natural numbers which have specified lengths. Secondly, the correctness of the SN P system is proved theoretically. However, the system can only be used to compute the product of any two binary natural numbers, but the product of any two decimal natural numbers often need to be computed in practical application. Therefore, it is necessary to construct a codin...