OK, let's crack this. We're given 156 and our task is to multiply it by 126. Essentially, we'll be adding 156 to itself 126 times.
Step 1: 0 + 156 = 156
Step 2: 156 + 156 = 312
Step 3: 312 + 156 = 468
Step 4: 468 + 156 = 624
Step 5: 624 + 156 = 780
Step 6: 780 + 156 = 936
Step 7: 936 + 156 = 1092
Step 8: 1092 + 156 = 1248
Step 9: 1248 + 156 = 1404
Step 10: 1404 + 156 = 1560
Step 11: 1560 + 156 = 1716
Step 12: 1716 + 156 = 1872
Step 13: 1872 + 156 = 2028
Step 14: 2028 + 156 = 2184
Step 15: 2184 + 156 = 2340
Step 16: 2340 + 156 = 2496
Step 17: 2496 + 156 = 2652
Step 18: 2652 + 156 = 2808
Step 19: 2808 + 156 = 2964
Step 20: 2964 + 156 = 3120
Step 21: 3120 + 156 = 3276
Step 22: 3276 + 156 = 3432
Step 23: 3432 + 156 = 3588
Step 24: 3588 + 156 = 3744
Step 25: 3744 + 156 = 3900
Step 26: 3900 + 156 = 4056
Step 27: 4056 + 156 = 4212
Step 28: 4212 + 156 = 4368
Step 29: 4368 + 156 = 4524
Step 30: 4524 + 156 = 4680
Step 31: 4680 + 156 = 4836
Step 32: 4836 + 156 = 4992
Step 33: 4992 + 156 = 5148
Step 34: 5148 + 156 = 5304
Step 35: 5304 + 156 = 5460
Step 36: 5460 + 156 = 5616
Step 37: 5616 + 156 = 5772
Step 38: 5772 + 156 = 5928
Step 39: 5928 + 156 = 6084
Step 40: 6084 + 156 = 6240
Step 41: 6240 + 156 = 6396
Step 42: 6396 + 156 = 6552
Step 43: 6552 + 156 = 6708
Step 44: 6708 + 156 = 6864
Step 45: 6864 + 156 = 7020
Step 46: 7020 + 156 = 7176
Step 47: 7176 + 156 = 7332
Step 48: 7332 + 156 = 7488
Step 49: 7488 + 156 = 7644
Step 50: 7644 + 156 = 7800
Step 51: 7800 + 156 = 7956
Step 52: 7956 + 156 = 8112
Step 53: 8112 + 156 = 8268
Step 54: 8268 + 156 = 8424
Step 55: 8424 + 156 = 8580
Step 56: 8580 + 156 = 8736
Step 57: 8736 + 156 = 8892
Step 58: 8892 + 156 = 9048
Step 59: 9048 + 156 = 9204
Step 60: 9204 + 156 = 9360
Step 61: 9360 + 156 = 9516
Step 62: 9516 + 156 = 9672
Step 63: 9672 + 156 = 9828
Step 64: 9828 + 156 = 9984
Step 65: 9984 + 156 = 10140
Step 66: 10140 + 156 = 10296
Step 67: 10296 + 156 = 10452
Step 68: 10452 + 156 = 10608
Step 69: 10608 + 156 = 10764
Step 70: 10764 + 156 = 10920
Step 71: 10920 + 156 = 11076
Step 72: 11076 + 156 = 11232
Step 73: 11232 + 156 = 11388
Step 74: 11388 + 156 = 11544
Step 75: 11544 + 156 = 11700
Step 76: 11700 + 156 = 11856
Step 77: 11856 + 156 = 12012
Step 78: 12012 + 156 = 12168
Step 79: 12168 + 156 = 12324
Step 80: 12324 + 156 = 12480
Step 81: 12480 + 156 = 12636
Step 82: 12636 + 156 = 12792
Step 83: 12792 + 156 = 12948
Step 84: 12948 + 156 = 13104
Step 85: 13104 + 156 = 13260
Step 86: 13260 + 156 = 13416
Step 87: 13416 + 156 = 13572
Step 88: 13572 + 156 = 13728
Step 89: 13728 + 156 = 13884
Step 90: 13884 + 156 = 14040
Step 91: 14040 + 156 = 14196
Step 92: 14196 + 156 = 14352
Step 93: 14352 + 156 = 14508
Step 94: 14508 + 156 = 14664
Step 95: 14664 + 156 = 14820
Step 96: 14820 + 156 = 14976
Step 97: 14976 + 156 = 15132
Step 98: 15132 + 156 = 15288
Step 99: 15288 + 156 = 15444
Step 100: 15444 + 156 = 15600
Step 101: 15600 + 156 = 15756
Step 102: 15756 + 156 = 15912
Step 103: 15912 + 156 = 16068
Step 104: 16068 + 156 = 16224
Step 105: 16224 + 156 = 16380
Step 106: 16380 + 156 = 16536
Step 107: 16536 + 156 = 16692
Step 108: 16692 + 156 = 16848
Step 109: 16848 + 156 = 17004
Step 110: 17004 + 156 = 17160
Step 111: 17160 + 156 = 17316
Step 112: 17316 + 156 = 17472
Step 113: 17472 + 156 = 17628
Step 114: 17628 + 156 = 17784
Step 115: 17784 + 156 = 17940
Step 116: 17940 + 156 = 18096
Step 117: 18096 + 156 = 18252
Step 118: 18252 + 156 = 18408
Step 119: 18408 + 156 = 18564
Step 120: 18564 + 156 = 18720
Step 121: 18720 + 156 = 18876
Step 122: 18876 + 156 = 19032
Step 123: 19032 + 156 = 19188
Step 124: 19188 + 156 = 19344
Step 125: 19344 + 156 = 19500
Step 126: 19500 + 156 = 19656

So, 156*126 = 19656