Alright, let's solve this math problem step by step. First, we have the number 51. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 13. So, we're going to take the number 51 and add it to itself 13 times.
Step 1: 0 + 51 = 51
Step 2: 51 + 51 = 102
Step 3: 102 + 51 = 153
Step 4: 153 + 51 = 204
Step 5: 204 + 51 = 255
Step 6: 255 + 51 = 306
Step 7: 306 + 51 = 357
Step 8: 357 + 51 = 408
Step 9: 408 + 51 = 459
Step 10: 459 + 51 = 510
Step 11: 510 + 51 = 561
Step 12: 561 + 51 = 612
Step 13: 612 + 51 = 663

So, 51*13 = 663