Assume that we send eight-digit numbers (data) plus two-digit check numbers, total of ten-digit numbers over network. Write the method of using two-digit check numbers with which receiver can check if first eight digit numbers were correctly transmitted and received by looking at last two-digit check numbers. Method must use concept of congruence modulo m. Select number m so that probability of getting same two-digit check number from 2 different eight-digit numbers is minimal.