OK, let's crack this. We're given 45 and our task is to multiply it by 9. Essentially, we'll be adding 45 to itself 9 times.
Step 1: 0 + 45 = 45
Step 2: 45 + 45 = 90
Step 3: 90 + 45 = 135
Step 4: 135 + 45 = 180
Step 5: 180 + 45 = 225
Step 6: 225 + 45 = 270
Step 7: 270 + 45 = 315
Step 8: 315 + 45 = 360
Step 9: 360 + 45 = 405

So, 45*9 = 405