OK, let's crack this. We're given 538 and our task is to multiply it by 79. Essentially, we'll be adding 538 to itself 79 times.
Step 1: 0 + 538 = 538
Step 2: 538 + 538 = 1076
Step 3: 1076 + 538 = 1614
Step 4: 1614 + 538 = 2152
Step 5: 2152 + 538 = 2690
Step 6: 2690 + 538 = 3228
Step 7: 3228 + 538 = 3766
Step 8: 3766 + 538 = 4304
Step 9: 4304 + 538 = 4842
Step 10: 4842 + 538 = 5380
Step 11: 5380 + 538 = 5918
Step 12: 5918 + 538 = 6456
Step 13: 6456 + 538 = 6994
Step 14: 6994 + 538 = 7532
Step 15: 7532 + 538 = 8070
Step 16: 8070 + 538 = 8608
Step 17: 8608 + 538 = 9146
Step 18: 9146 + 538 = 9684
Step 19: 9684 + 538 = 10222
Step 20: 10222 + 538 = 10760
Step 21: 10760 + 538 = 11298
Step 22: 11298 + 538 = 11836
Step 23: 11836 + 538 = 12374
Step 24: 12374 + 538 = 12912
Step 25: 12912 + 538 = 13450
Step 26: 13450 + 538 = 13988
Step 27: 13988 + 538 = 14526
Step 28: 14526 + 538 = 15064
Step 29: 15064 + 538 = 15602
Step 30: 15602 + 538 = 16140
Step 31: 16140 + 538 = 16678
Step 32: 16678 + 538 = 17216
Step 33: 17216 + 538 = 17754
Step 34: 17754 + 538 = 18292
Step 35: 18292 + 538 = 18830
Step 36: 18830 + 538 = 19368
Step 37: 19368 + 538 = 19906
Step 38: 19906 + 538 = 20444
Step 39: 20444 + 538 = 20982
Step 40: 20982 + 538 = 21520
Step 41: 21520 + 538 = 22058
Step 42: 22058 + 538 = 22596
Step 43: 22596 + 538 = 23134
Step 44: 23134 + 538 = 23672
Step 45: 23672 + 538 = 24210
Step 46: 24210 + 538 = 24748
Step 47: 24748 + 538 = 25286
Step 48: 25286 + 538 = 25824
Step 49: 25824 + 538 = 26362
Step 50: 26362 + 538 = 26900
Step 51: 26900 + 538 = 27438
Step 52: 27438 + 538 = 27976
Step 53: 27976 + 538 = 28514
Step 54: 28514 + 538 = 29052
Step 55: 29052 + 538 = 29590
Step 56: 29590 + 538 = 30128
Step 57: 30128 + 538 = 30666
Step 58: 30666 + 538 = 31204
Step 59: 31204 + 538 = 31742
Step 60: 31742 + 538 = 32280
Step 61: 32280 + 538 = 32818
Step 62: 32818 + 538 = 33356
Step 63: 33356 + 538 = 33894
Step 64: 33894 + 538 = 34432
Step 65: 34432 + 538 = 34970
Step 66: 34970 + 538 = 35508
Step 67: 35508 + 538 = 36046
Step 68: 36046 + 538 = 36584
Step 69: 36584 + 538 = 37122
Step 70: 37122 + 538 = 37660
Step 71: 37660 + 538 = 38198
Step 72: 38198 + 538 = 38736
Step 73: 38736 + 538 = 39274
Step 74: 39274 + 538 = 39812
Step 75: 39812 + 538 = 40350
Step 76: 40350 + 538 = 40888
Step 77: 40888 + 538 = 41426
Step 78: 41426 + 538 = 41964
Step 79: 41964 + 538 = 42502

So, 538*79 = 42502