OK, let's crack this. We're given 945 and our task is to multiply it by 18. Essentially, we'll be adding 945 to itself 18 times.
Step 1: 0 + 945 = 945
Step 2: 945 + 945 = 1890
Step 3: 1890 + 945 = 2835
Step 4: 2835 + 945 = 3780
Step 5: 3780 + 945 = 4725
Step 6: 4725 + 945 = 5670
Step 7: 5670 + 945 = 6615
Step 8: 6615 + 945 = 7560
Step 9: 7560 + 945 = 8505
Step 10: 8505 + 945 = 9450
Step 11: 9450 + 945 = 10395
Step 12: 10395 + 945 = 11340
Step 13: 11340 + 945 = 12285
Step 14: 12285 + 945 = 13230
Step 15: 13230 + 945 = 14175
Step 16: 14175 + 945 = 15120
Step 17: 15120 + 945 = 16065
Step 18: 16065 + 945 = 17010

So, 945*18 = 17010