OK, let's crack this. We're given 12 and our task is to multiply it by 154. Essentially, we'll be adding 12 to itself 154 times.
Step 1: 0 + 12 = 12
Step 2: 12 + 12 = 24
Step 3: 24 + 12 = 36
Step 4: 36 + 12 = 48
Step 5: 48 + 12 = 60
Step 6: 60 + 12 = 72
Step 7: 72 + 12 = 84
Step 8: 84 + 12 = 96
Step 9: 96 + 12 = 108
Step 10: 108 + 12 = 120
Step 11: 120 + 12 = 132
Step 12: 132 + 12 = 144
Step 13: 144 + 12 = 156
Step 14: 156 + 12 = 168
Step 15: 168 + 12 = 180
Step 16: 180 + 12 = 192
Step 17: 192 + 12 = 204
Step 18: 204 + 12 = 216
Step 19: 216 + 12 = 228
Step 20: 228 + 12 = 240
Step 21: 240 + 12 = 252
Step 22: 252 + 12 = 264
Step 23: 264 + 12 = 276
Step 24: 276 + 12 = 288
Step 25: 288 + 12 = 300
Step 26: 300 + 12 = 312
Step 27: 312 + 12 = 324
Step 28: 324 + 12 = 336
Step 29: 336 + 12 = 348
Step 30: 348 + 12 = 360
Step 31: 360 + 12 = 372
Step 32: 372 + 12 = 384
Step 33: 384 + 12 = 396
Step 34: 396 + 12 = 408
Step 35: 408 + 12 = 420
Step 36: 420 + 12 = 432
Step 37: 432 + 12 = 444
Step 38: 444 + 12 = 456
Step 39: 456 + 12 = 468
Step 40: 468 + 12 = 480
Step 41: 480 + 12 = 492
Step 42: 492 + 12 = 504
Step 43: 504 + 12 = 516
Step 44: 516 + 12 = 528
Step 45: 528 + 12 = 540
Step 46: 540 + 12 = 552
Step 47: 552 + 12 = 564
Step 48: 564 + 12 = 576
Step 49: 576 + 12 = 588
Step 50: 588 + 12 = 600
Step 51: 600 + 12 = 612
Step 52: 612 + 12 = 624
Step 53: 624 + 12 = 636
Step 54: 636 + 12 = 648
Step 55: 648 + 12 = 660
Step 56: 660 + 12 = 672
Step 57: 672 + 12 = 684
Step 58: 684 + 12 = 696
Step 59: 696 + 12 = 708
Step 60: 708 + 12 = 720
Step 61: 720 + 12 = 732
Step 62: 732 + 12 = 744
Step 63: 744 + 12 = 756
Step 64: 756 + 12 = 768
Step 65: 768 + 12 = 780
Step 66: 780 + 12 = 792
Step 67: 792 + 12 = 804
Step 68: 804 + 12 = 816
Step 69: 816 + 12 = 828
Step 70: 828 + 12 = 840
Step 71: 840 + 12 = 852
Step 72: 852 + 12 = 864
Step 73: 864 + 12 = 876
Step 74: 876 + 12 = 888
Step 75: 888 + 12 = 900
Step 76: 900 + 12 = 912
Step 77: 912 + 12 = 924
Step 78: 924 + 12 = 936
Step 79: 936 + 12 = 948
Step 80: 948 + 12 = 960
Step 81: 960 + 12 = 972
Step 82: 972 + 12 = 984
Step 83: 984 + 12 = 996
Step 84: 996 + 12 = 1008
Step 85: 1008 + 12 = 1020
Step 86: 1020 + 12 = 1032
Step 87: 1032 + 12 = 1044
Step 88: 1044 + 12 = 1056
Step 89: 1056 + 12 = 1068
Step 90: 1068 + 12 = 1080
Step 91: 1080 + 12 = 1092
Step 92: 1092 + 12 = 1104
Step 93: 1104 + 12 = 1116
Step 94: 1116 + 12 = 1128
Step 95: 1128 + 12 = 1140
Step 96: 1140 + 12 = 1152
Step 97: 1152 + 12 = 1164
Step 98: 1164 + 12 = 1176
Step 99: 1176 + 12 = 1188
Step 100: 1188 + 12 = 1200
Step 101: 1200 + 12 = 1212
Step 102: 1212 + 12 = 1224
Step 103: 1224 + 12 = 1236
Step 104: 1236 + 12 = 1248
Step 105: 1248 + 12 = 1260
Step 106: 1260 + 12 = 1272
Step 107: 1272 + 12 = 1284
Step 108: 1284 + 12 = 1296
Step 109: 1296 + 12 = 1308
Step 110: 1308 + 12 = 1320
Step 111: 1320 + 12 = 1332
Step 112: 1332 + 12 = 1344
Step 113: 1344 + 12 = 1356
Step 114: 1356 + 12 = 1368
Step 115: 1368 + 12 = 1380
Step 116: 1380 + 12 = 1392
Step 117: 1392 + 12 = 1404
Step 118: 1404 + 12 = 1416
Step 119: 1416 + 12 = 1428
Step 120: 1428 + 12 = 1440
Step 121: 1440 + 12 = 1452
Step 122: 1452 + 12 = 1464
Step 123: 1464 + 12 = 1476
Step 124: 1476 + 12 = 1488
Step 125: 1488 + 12 = 1500
Step 126: 1500 + 12 = 1512
Step 127: 1512 + 12 = 1524
Step 128: 1524 + 12 = 1536
Step 129: 1536 + 12 = 1548
Step 130: 1548 + 12 = 1560
Step 131: 1560 + 12 = 1572
Step 132: 1572 + 12 = 1584
Step 133: 1584 + 12 = 1596
Step 134: 1596 + 12 = 1608
Step 135: 1608 + 12 = 1620
Step 136: 1620 + 12 = 1632
Step 137: 1632 + 12 = 1644
Step 138: 1644 + 12 = 1656
Step 139: 1656 + 12 = 1668
Step 140: 1668 + 12 = 1680
Step 141: 1680 + 12 = 1692
Step 142: 1692 + 12 = 1704
Step 143: 1704 + 12 = 1716
Step 144: 1716 + 12 = 1728
Step 145: 1728 + 12 = 1740
Step 146: 1740 + 12 = 1752
Step 147: 1752 + 12 = 1764
Step 148: 1764 + 12 = 1776
Step 149: 1776 + 12 = 1788
Step 150: 1788 + 12 = 1800
Step 151: 1800 + 12 = 1812
Step 152: 1812 + 12 = 1824
Step 153: 1824 + 12 = 1836
Step 154: 1836 + 12 = 1848

So, 12*154 = 1848