OK, let's crack this. We're given 728 and our task is to multiply it by 18. Essentially, we'll be adding 728 to itself 18 times.
Step 1: 0 + 728 = 728
Step 2: 728 + 728 = 1456
Step 3: 1456 + 728 = 2184
Step 4: 2184 + 728 = 2912
Step 5: 2912 + 728 = 3640
Step 6: 3640 + 728 = 4368
Step 7: 4368 + 728 = 5096
Step 8: 5096 + 728 = 5824
Step 9: 5824 + 728 = 6552
Step 10: 6552 + 728 = 7280
Step 11: 7280 + 728 = 8008
Step 12: 8008 + 728 = 8736
Step 13: 8736 + 728 = 9464
Step 14: 9464 + 728 = 10192
Step 15: 10192 + 728 = 10920
Step 16: 10920 + 728 = 11648
Step 17: 11648 + 728 = 12376
Step 18: 12376 + 728 = 13104

So, 728*18 = 13104