C'mon. . We know how to do this! . Multiply 5 by ANY number you want!! . I say infinity. . Actually thats impossible. . Ok, 8. . Ones digit? . 40, so it's 0. . How about multiply by 2 and 3^2? (18) . 90, so 0. . See? . Easy as pi. . Hope I helped! . Any questions, ask away!