OK, let's crack this. We're given 154 and our task is to multiply it by 129. Essentially, we'll be adding 154 to itself 129 times.
Step 1: 0 + 154 = 154
Step 2: 154 + 154 = 308
Step 3: 308 + 154 = 462
Step 4: 462 + 154 = 616
Step 5: 616 + 154 = 770
Step 6: 770 + 154 = 924
Step 7: 924 + 154 = 1078
Step 8: 1078 + 154 = 1232
Step 9: 1232 + 154 = 1386
Step 10: 1386 + 154 = 1540
Step 11: 1540 + 154 = 1694
Step 12: 1694 + 154 = 1848
Step 13: 1848 + 154 = 2002
Step 14: 2002 + 154 = 2156
Step 15: 2156 + 154 = 2310
Step 16: 2310 + 154 = 2464
Step 17: 2464 + 154 = 2618
Step 18: 2618 + 154 = 2772
Step 19: 2772 + 154 = 2926
Step 20: 2926 + 154 = 3080
Step 21: 3080 + 154 = 3234
Step 22: 3234 + 154 = 3388
Step 23: 3388 + 154 = 3542
Step 24: 3542 + 154 = 3696
Step 25: 3696 + 154 = 3850
Step 26: 3850 + 154 = 4004
Step 27: 4004 + 154 = 4158
Step 28: 4158 + 154 = 4312
Step 29: 4312 + 154 = 4466
Step 30: 4466 + 154 = 4620
Step 31: 4620 + 154 = 4774
Step 32: 4774 + 154 = 4928
Step 33: 4928 + 154 = 5082
Step 34: 5082 + 154 = 5236
Step 35: 5236 + 154 = 5390
Step 36: 5390 + 154 = 5544
Step 37: 5544 + 154 = 5698
Step 38: 5698 + 154 = 5852
Step 39: 5852 + 154 = 6006
Step 40: 6006 + 154 = 6160
Step 41: 6160 + 154 = 6314
Step 42: 6314 + 154 = 6468
Step 43: 6468 + 154 = 6622
Step 44: 6622 + 154 = 6776
Step 45: 6776 + 154 = 6930
Step 46: 6930 + 154 = 7084
Step 47: 7084 + 154 = 7238
Step 48: 7238 + 154 = 7392
Step 49: 7392 + 154 = 7546
Step 50: 7546 + 154 = 7700
Step 51: 7700 + 154 = 7854
Step 52: 7854 + 154 = 8008
Step 53: 8008 + 154 = 8162
Step 54: 8162 + 154 = 8316
Step 55: 8316 + 154 = 8470
Step 56: 8470 + 154 = 8624
Step 57: 8624 + 154 = 8778
Step 58: 8778 + 154 = 8932
Step 59: 8932 + 154 = 9086
Step 60: 9086 + 154 = 9240
Step 61: 9240 + 154 = 9394
Step 62: 9394 + 154 = 9548
Step 63: 9548 + 154 = 9702
Step 64: 9702 + 154 = 9856
Step 65: 9856 + 154 = 10010
Step 66: 10010 + 154 = 10164
Step 67: 10164 + 154 = 10318
Step 68: 10318 + 154 = 10472
Step 69: 10472 + 154 = 10626
Step 70: 10626 + 154 = 10780
Step 71: 10780 + 154 = 10934
Step 72: 10934 + 154 = 11088
Step 73: 11088 + 154 = 11242
Step 74: 11242 + 154 = 11396
Step 75: 11396 + 154 = 11550
Step 76: 11550 + 154 = 11704
Step 77: 11704 + 154 = 11858
Step 78: 11858 + 154 = 12012
Step 79: 12012 + 154 = 12166
Step 80: 12166 + 154 = 12320
Step 81: 12320 + 154 = 12474
Step 82: 12474 + 154 = 12628
Step 83: 12628 + 154 = 12782
Step 84: 12782 + 154 = 12936
Step 85: 12936 + 154 = 13090
Step 86: 13090 + 154 = 13244
Step 87: 13244 + 154 = 13398
Step 88: 13398 + 154 = 13552
Step 89: 13552 + 154 = 13706
Step 90: 13706 + 154 = 13860
Step 91: 13860 + 154 = 14014
Step 92: 14014 + 154 = 14168
Step 93: 14168 + 154 = 14322
Step 94: 14322 + 154 = 14476
Step 95: 14476 + 154 = 14630
Step 96: 14630 + 154 = 14784
Step 97: 14784 + 154 = 14938
Step 98: 14938 + 154 = 15092
Step 99: 15092 + 154 = 15246
Step 100: 15246 + 154 = 15400
Step 101: 15400 + 154 = 15554
Step 102: 15554 + 154 = 15708
Step 103: 15708 + 154 = 15862
Step 104: 15862 + 154 = 16016
Step 105: 16016 + 154 = 16170
Step 106: 16170 + 154 = 16324
Step 107: 16324 + 154 = 16478
Step 108: 16478 + 154 = 16632
Step 109: 16632 + 154 = 16786
Step 110: 16786 + 154 = 16940
Step 111: 16940 + 154 = 17094
Step 112: 17094 + 154 = 17248
Step 113: 17248 + 154 = 17402
Step 114: 17402 + 154 = 17556
Step 115: 17556 + 154 = 17710
Step 116: 17710 + 154 = 17864
Step 117: 17864 + 154 = 18018
Step 118: 18018 + 154 = 18172
Step 119: 18172 + 154 = 18326
Step 120: 18326 + 154 = 18480
Step 121: 18480 + 154 = 18634
Step 122: 18634 + 154 = 18788
Step 123: 18788 + 154 = 18942
Step 124: 18942 + 154 = 19096
Step 125: 19096 + 154 = 19250
Step 126: 19250 + 154 = 19404
Step 127: 19404 + 154 = 19558
Step 128: 19558 + 154 = 19712
Step 129: 19712 + 154 = 19866

So, 154*129 = 19866