Let's roll up our sleeves and solve this. We have 817 and we're going to multiply it by 18, essentially adding 817 to itself 18 times.
Step 1: 0 + 817 = 817
Step 2: 817 + 817 = 1634
Step 3: 1634 + 817 = 2451
Step 4: 2451 + 817 = 3268
Step 5: 3268 + 817 = 4085
Step 6: 4085 + 817 = 4902
Step 7: 4902 + 817 = 5719
Step 8: 5719 + 817 = 6536
Step 9: 6536 + 817 = 7353
Step 10: 7353 + 817 = 8170
Step 11: 8170 + 817 = 8987
Step 12: 8987 + 817 = 9804
Step 13: 9804 + 817 = 10621
Step 14: 10621 + 817 = 11438
Step 15: 11438 + 817 = 12255
Step 16: 12255 + 817 = 13072
Step 17: 13072 + 817 = 13889
Step 18: 13889 + 817 = 14706

So, 817*18 = 14706