OK, let's work through this together. We're starting with 755 and we're going to multiply it by 18, which means we add 755 to itself 18 times.
Step 1: 0 + 755 = 755
Step 2: 755 + 755 = 1510
Step 3: 1510 + 755 = 2265
Step 4: 2265 + 755 = 3020
Step 5: 3020 + 755 = 3775
Step 6: 3775 + 755 = 4530
Step 7: 4530 + 755 = 5285
Step 8: 5285 + 755 = 6040
Step 9: 6040 + 755 = 6795
Step 10: 6795 + 755 = 7550
Step 11: 7550 + 755 = 8305
Step 12: 8305 + 755 = 9060
Step 13: 9060 + 755 = 9815
Step 14: 9815 + 755 = 10570
Step 15: 10570 + 755 = 11325
Step 16: 11325 + 755 = 12080
Step 17: 12080 + 755 = 12835
Step 18: 12835 + 755 = 13590

So, 755*18 = 13590