OK, let's crack this. We're given 42 and our task is to multiply it by 38. Essentially, we'll be adding 42 to itself 38 times.
Step 1: 0 + 42 = 42
Step 2: 42 + 42 = 84
Step 3: 84 + 42 = 126
Step 4: 126 + 42 = 168
Step 5: 168 + 42 = 210
Step 6: 210 + 42 = 252
Step 7: 252 + 42 = 294
Step 8: 294 + 42 = 336
Step 9: 336 + 42 = 378
Step 10: 378 + 42 = 420
Step 11: 420 + 42 = 462
Step 12: 462 + 42 = 504
Step 13: 504 + 42 = 546
Step 14: 546 + 42 = 588
Step 15: 588 + 42 = 630
Step 16: 630 + 42 = 672
Step 17: 672 + 42 = 714
Step 18: 714 + 42 = 756
Step 19: 756 + 42 = 798
Step 20: 798 + 42 = 840
Step 21: 840 + 42 = 882
Step 22: 882 + 42 = 924
Step 23: 924 + 42 = 966
Step 24: 966 + 42 = 1008
Step 25: 1008 + 42 = 1050
Step 26: 1050 + 42 = 1092
Step 27: 1092 + 42 = 1134
Step 28: 1134 + 42 = 1176
Step 29: 1176 + 42 = 1218
Step 30: 1218 + 42 = 1260
Step 31: 1260 + 42 = 1302
Step 32: 1302 + 42 = 1344
Step 33: 1344 + 42 = 1386
Step 34: 1386 + 42 = 1428
Step 35: 1428 + 42 = 1470
Step 36: 1470 + 42 = 1512
Step 37: 1512 + 42 = 1554
Step 38: 1554 + 42 = 1596

So, 42*38 = 1596