Let's roll up our sleeves and solve this. We have 509 and we're going to multiply it by 18, essentially adding 509 to itself 18 times.
Step 1: 0 + 509 = 509
Step 2: 509 + 509 = 1018
Step 3: 1018 + 509 = 1527
Step 4: 1527 + 509 = 2036
Step 5: 2036 + 509 = 2545
Step 6: 2545 + 509 = 3054
Step 7: 3054 + 509 = 3563
Step 8: 3563 + 509 = 4072
Step 9: 4072 + 509 = 4581
Step 10: 4581 + 509 = 5090
Step 11: 5090 + 509 = 5599
Step 12: 5599 + 509 = 6108
Step 13: 6108 + 509 = 6617
Step 14: 6617 + 509 = 7126
Step 15: 7126 + 509 = 7635
Step 16: 7635 + 509 = 8144
Step 17: 8144 + 509 = 8653
Step 18: 8653 + 509 = 9162

So, 509*18 = 9162