OK, let's crack this. We're given 555 and our task is to multiply it by 13. Essentially, we'll be adding 555 to itself 13 times.
Step 1: 0 + 555 = 555
Step 2: 555 + 555 = 1110
Step 3: 1110 + 555 = 1665
Step 4: 1665 + 555 = 2220
Step 5: 2220 + 555 = 2775
Step 6: 2775 + 555 = 3330
Step 7: 3330 + 555 = 3885
Step 8: 3885 + 555 = 4440
Step 9: 4440 + 555 = 4995
Step 10: 4995 + 555 = 5550
Step 11: 5550 + 555 = 6105
Step 12: 6105 + 555 = 6660
Step 13: 6660 + 555 = 7215

So, 555*13 = 7215