OK, let's crack this. We're given 424 and our task is to multiply it by 18. Essentially, we'll be adding 424 to itself 18 times.
Step 1: 0 + 424 = 424
Step 2: 424 + 424 = 848
Step 3: 848 + 424 = 1272
Step 4: 1272 + 424 = 1696
Step 5: 1696 + 424 = 2120
Step 6: 2120 + 424 = 2544
Step 7: 2544 + 424 = 2968
Step 8: 2968 + 424 = 3392
Step 9: 3392 + 424 = 3816
Step 10: 3816 + 424 = 4240
Step 11: 4240 + 424 = 4664
Step 12: 4664 + 424 = 5088
Step 13: 5088 + 424 = 5512
Step 14: 5512 + 424 = 5936
Step 15: 5936 + 424 = 6360
Step 16: 6360 + 424 = 6784
Step 17: 6784 + 424 = 7208
Step 18: 7208 + 424 = 7632

So, 424*18 = 7632