OK, let's crack this. We're given 636 and our task is to multiply it by 38. Essentially, we'll be adding 636 to itself 38 times.
Step 1: 0 + 636 = 636
Step 2: 636 + 636 = 1272
Step 3: 1272 + 636 = 1908
Step 4: 1908 + 636 = 2544
Step 5: 2544 + 636 = 3180
Step 6: 3180 + 636 = 3816
Step 7: 3816 + 636 = 4452
Step 8: 4452 + 636 = 5088
Step 9: 5088 + 636 = 5724
Step 10: 5724 + 636 = 6360
Step 11: 6360 + 636 = 6996
Step 12: 6996 + 636 = 7632
Step 13: 7632 + 636 = 8268
Step 14: 8268 + 636 = 8904
Step 15: 8904 + 636 = 9540
Step 16: 9540 + 636 = 10176
Step 17: 10176 + 636 = 10812
Step 18: 10812 + 636 = 11448
Step 19: 11448 + 636 = 12084
Step 20: 12084 + 636 = 12720
Step 21: 12720 + 636 = 13356
Step 22: 13356 + 636 = 13992
Step 23: 13992 + 636 = 14628
Step 24: 14628 + 636 = 15264
Step 25: 15264 + 636 = 15900
Step 26: 15900 + 636 = 16536
Step 27: 16536 + 636 = 17172
Step 28: 17172 + 636 = 17808
Step 29: 17808 + 636 = 18444
Step 30: 18444 + 636 = 19080
Step 31: 19080 + 636 = 19716
Step 32: 19716 + 636 = 20352
Step 33: 20352 + 636 = 20988
Step 34: 20988 + 636 = 21624
Step 35: 21624 + 636 = 22260
Step 36: 22260 + 636 = 22896
Step 37: 22896 + 636 = 23532
Step 38: 23532 + 636 = 24168

So, 636*38 = 24168