OK, let's crack this. We're given 13 and our task is to multiply it by 13. Essentially, we'll be adding 13 to itself 13 times.
Step 1: 0 + 13 = 13
Step 2: 13 + 13 = 26
Step 3: 26 + 13 = 39
Step 4: 39 + 13 = 52
Step 5: 52 + 13 = 65
Step 6: 65 + 13 = 78
Step 7: 78 + 13 = 91
Step 8: 91 + 13 = 104
Step 9: 104 + 13 = 117
Step 10: 117 + 13 = 130
Step 11: 130 + 13 = 143
Step 12: 143 + 13 = 156
Step 13: 156 + 13 = 169

So, 13*13 = 169