Let's get this math done. We have 665 and we're going to multiply it by 16. This is the same as taking 665 and adding it to itself 16 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
Step 14: 8645 + 665 = 9310
Step 15: 9310 + 665 = 9975
Step 16: 9975 + 665 = 10640

So, 665*16 = 10640