Let's get this math done. We have 879 and we're going to multiply it by 103. This is the same as taking 879 and adding it to itself 103 times.
Step 1: 0 + 879 = 879
Step 2: 879 + 879 = 1758
Step 3: 1758 + 879 = 2637
Step 4: 2637 + 879 = 3516
Step 5: 3516 + 879 = 4395
Step 6: 4395 + 879 = 5274
Step 7: 5274 + 879 = 6153
Step 8: 6153 + 879 = 7032
Step 9: 7032 + 879 = 7911
Step 10: 7911 + 879 = 8790
Step 11: 8790 + 879 = 9669
Step 12: 9669 + 879 = 10548
Step 13: 10548 + 879 = 11427
Step 14: 11427 + 879 = 12306
Step 15: 12306 + 879 = 13185
Step 16: 13185 + 879 = 14064
Step 17: 14064 + 879 = 14943
Step 18: 14943 + 879 = 15822
Step 19: 15822 + 879 = 16701
Step 20: 16701 + 879 = 17580
Step 21: 17580 + 879 = 18459
Step 22: 18459 + 879 = 19338
Step 23: 19338 + 879 = 20217
Step 24: 20217 + 879 = 21096
Step 25: 21096 + 879 = 21975
Step 26: 21975 + 879 = 22854
Step 27: 22854 + 879 = 23733
Step 28: 23733 + 879 = 24612
Step 29: 24612 + 879 = 25491
Step 30: 25491 + 879 = 26370
Step 31: 26370 + 879 = 27249
Step 32: 27249 + 879 = 28128
Step 33: 28128 + 879 = 29007
Step 34: 29007 + 879 = 29886
Step 35: 29886 + 879 = 30765
Step 36: 30765 + 879 = 31644
Step 37: 31644 + 879 = 32523
Step 38: 32523 + 879 = 33402
Step 39: 33402 + 879 = 34281
Step 40: 34281 + 879 = 35160
Step 41: 35160 + 879 = 36039
Step 42: 36039 + 879 = 36918
Step 43: 36918 + 879 = 37797
Step 44: 37797 + 879 = 38676
Step 45: 38676 + 879 = 39555
Step 46: 39555 + 879 = 40434
Step 47: 40434 + 879 = 41313
Step 48: 41313 + 879 = 42192
Step 49: 42192 + 879 = 43071
Step 50: 43071 + 879 = 43950
Step 51: 43950 + 879 = 44829
Step 52: 44829 + 879 = 45708
Step 53: 45708 + 879 = 46587
Step 54: 46587 + 879 = 47466
Step 55: 47466 + 879 = 48345
Step 56: 48345 + 879 = 49224
Step 57: 49224 + 879 = 50103
Step 58: 50103 + 879 = 50982
Step 59: 50982 + 879 = 51861
Step 60: 51861 + 879 = 52740
Step 61: 52740 + 879 = 53619
Step 62: 53619 + 879 = 54498
Step 63: 54498 + 879 = 55377
Step 64: 55377 + 879 = 56256
Step 65: 56256 + 879 = 57135
Step 66: 57135 + 879 = 58014
Step 67: 58014 + 879 = 58893
Step 68: 58893 + 879 = 59772
Step 69: 59772 + 879 = 60651
Step 70: 60651 + 879 = 61530
Step 71: 61530 + 879 = 62409
Step 72: 62409 + 879 = 63288
Step 73: 63288 + 879 = 64167
Step 74: 64167 + 879 = 65046
Step 75: 65046 + 879 = 65925
Step 76: 65925 + 879 = 66804
Step 77: 66804 + 879 = 67683
Step 78: 67683 + 879 = 68562
Step 79: 68562 + 879 = 69441
Step 80: 69441 + 879 = 70320
Step 81: 70320 + 879 = 71199
Step 82: 71199 + 879 = 72078
Step 83: 72078 + 879 = 72957
Step 84: 72957 + 879 = 73836
Step 85: 73836 + 879 = 74715
Step 86: 74715 + 879 = 75594
Step 87: 75594 + 879 = 76473
Step 88: 76473 + 879 = 77352
Step 89: 77352 + 879 = 78231
Step 90: 78231 + 879 = 79110
Step 91: 79110 + 879 = 79989
Step 92: 79989 + 879 = 80868
Step 93: 80868 + 879 = 81747
Step 94: 81747 + 879 = 82626
Step 95: 82626 + 879 = 83505
Step 96: 83505 + 879 = 84384
Step 97: 84384 + 879 = 85263
Step 98: 85263 + 879 = 86142
Step 99: 86142 + 879 = 87021
Step 100: 87021 + 879 = 87900
Step 101: 87900 + 879 = 88779
Step 102: 88779 + 879 = 89658
Step 103: 89658 + 879 = 90537

So, 879*103 = 90537