In the paper, we propose a new method of modular multiplication computation, based on Residue Number System. We use an approximate method to find the approximate method a residue from division of a multiplication on the given module. We substitute expensive modular operations, by fast bit right shift operations and taking low bits. The carried-out simulation on Kintex7 XC7K70T board showed that the offered method allows to win in time on average for 75%, and in the area - on average for 80% relatively to modified method from work [1] that makes it more applicable for the hardware implementation of the cryptography primitives constructed over a simple finite field.