Let's get this math done. We have 819 and we're going to multiply it by 16. This is the same as taking 819 and adding it to itself 16 times.
Step 1: 0 + 819 = 819
Step 2: 819 + 819 = 1638
Step 3: 1638 + 819 = 2457
Step 4: 2457 + 819 = 3276
Step 5: 3276 + 819 = 4095
Step 6: 4095 + 819 = 4914
Step 7: 4914 + 819 = 5733
Step 8: 5733 + 819 = 6552
Step 9: 6552 + 819 = 7371
Step 10: 7371 + 819 = 8190
Step 11: 8190 + 819 = 9009
Step 12: 9009 + 819 = 9828
Step 13: 9828 + 819 = 10647
Step 14: 10647 + 819 = 11466
Step 15: 11466 + 819 = 12285
Step 16: 12285 + 819 = 13104

So, 819*16 = 13104