OK, let's crack this. We're given 513 and our task is to multiply it by 12. Essentially, we'll be adding 513 to itself 12 times.
Step 1: 0 + 513 = 513
Step 2: 513 + 513 = 1026
Step 3: 1026 + 513 = 1539
Step 4: 1539 + 513 = 2052
Step 5: 2052 + 513 = 2565
Step 6: 2565 + 513 = 3078
Step 7: 3078 + 513 = 3591
Step 8: 3591 + 513 = 4104
Step 9: 4104 + 513 = 4617
Step 10: 4617 + 513 = 5130
Step 11: 5130 + 513 = 5643
Step 12: 5643 + 513 = 6156

So, 513*12 = 6156