Let's roll up our sleeves and solve this. We have 427 and we're going to multiply it by 9, essentially adding 427 to itself 9 times.
Step 1: 0 + 427 = 427
Step 2: 427 + 427 = 854
Step 3: 854 + 427 = 1281
Step 4: 1281 + 427 = 1708
Step 5: 1708 + 427 = 2135
Step 6: 2135 + 427 = 2562
Step 7: 2562 + 427 = 2989
Step 8: 2989 + 427 = 3416
Step 9: 3416 + 427 = 3843

So, 427*9 = 3843