Alright, let's solve this math problem step by step. First, we have the number 879. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 129. So, we're going to take the number 879 and add it to itself 129 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
Step 104: 90537 + 879 = 91416
Step 105: 91416 + 879 = 92295
Step 106: 92295 + 879 = 93174
Step 107: 93174 + 879 = 94053
Step 108: 94053 + 879 = 94932
Step 109: 94932 + 879 = 95811
Step 110: 95811 + 879 = 96690
Step 111: 96690 + 879 = 97569
Step 112: 97569 + 879 = 98448
Step 113: 98448 + 879 = 99327
Step 114: 99327 + 879 = 100206
Step 115: 100206 + 879 = 101085
Step 116: 101085 + 879 = 101964
Step 117: 101964 + 879 = 102843
Step 118: 102843 + 879 = 103722
Step 119: 103722 + 879 = 104601
Step 120: 104601 + 879 = 105480
Step 121: 105480 + 879 = 106359
Step 122: 106359 + 879 = 107238
Step 123: 107238 + 879 = 108117
Step 124: 108117 + 879 = 108996
Step 125: 108996 + 879 = 109875
Step 126: 109875 + 879 = 110754
Step 127: 110754 + 879 = 111633
Step 128: 111633 + 879 = 112512
Step 129: 112512 + 879 = 113391

So, 879*129 = 113391