Alright, let's solve this math problem step by step. First, we have the number 665. 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 665 and add it to itself 13 times.
Step 1: 0 + 665 = 665
Step 2: 665 + 665 = 1330
Step 3: 1330 + 665 = 1995
Step 4: 1995 + 665 = 2660
Step 5: 2660 + 665 = 3325
Step 6: 3325 + 665 = 3990
Step 7: 3990 + 665 = 4655
Step 8: 4655 + 665 = 5320
Step 9: 5320 + 665 = 5985
Step 10: 5985 + 665 = 6650
Step 11: 6650 + 665 = 7315
Step 12: 7315 + 665 = 7980
Step 13: 7980 + 665 = 8645

So, 665*13 = 8645