Let's roll up our sleeves and solve this. We have 438 and we're going to multiply it by 166, essentially adding 438 to itself 166 times.
Step 1: 0 + 438 = 438
Step 2: 438 + 438 = 876
Step 3: 876 + 438 = 1314
Step 4: 1314 + 438 = 1752
Step 5: 1752 + 438 = 2190
Step 6: 2190 + 438 = 2628
Step 7: 2628 + 438 = 3066
Step 8: 3066 + 438 = 3504
Step 9: 3504 + 438 = 3942
Step 10: 3942 + 438 = 4380
Step 11: 4380 + 438 = 4818
Step 12: 4818 + 438 = 5256
Step 13: 5256 + 438 = 5694
Step 14: 5694 + 438 = 6132
Step 15: 6132 + 438 = 6570
Step 16: 6570 + 438 = 7008
Step 17: 7008 + 438 = 7446
Step 18: 7446 + 438 = 7884
Step 19: 7884 + 438 = 8322
Step 20: 8322 + 438 = 8760
Step 21: 8760 + 438 = 9198
Step 22: 9198 + 438 = 9636
Step 23: 9636 + 438 = 10074
Step 24: 10074 + 438 = 10512
Step 25: 10512 + 438 = 10950
Step 26: 10950 + 438 = 11388
Step 27: 11388 + 438 = 11826
Step 28: 11826 + 438 = 12264
Step 29: 12264 + 438 = 12702
Step 30: 12702 + 438 = 13140
Step 31: 13140 + 438 = 13578
Step 32: 13578 + 438 = 14016
Step 33: 14016 + 438 = 14454
Step 34: 14454 + 438 = 14892
Step 35: 14892 + 438 = 15330
Step 36: 15330 + 438 = 15768
Step 37: 15768 + 438 = 16206
Step 38: 16206 + 438 = 16644
Step 39: 16644 + 438 = 17082
Step 40: 17082 + 438 = 17520
Step 41: 17520 + 438 = 17958
Step 42: 17958 + 438 = 18396
Step 43: 18396 + 438 = 18834
Step 44: 18834 + 438 = 19272
Step 45: 19272 + 438 = 19710
Step 46: 19710 + 438 = 20148
Step 47: 20148 + 438 = 20586
Step 48: 20586 + 438 = 21024
Step 49: 21024 + 438 = 21462
Step 50: 21462 + 438 = 21900
Step 51: 21900 + 438 = 22338
Step 52: 22338 + 438 = 22776
Step 53: 22776 + 438 = 23214
Step 54: 23214 + 438 = 23652
Step 55: 23652 + 438 = 24090
Step 56: 24090 + 438 = 24528
Step 57: 24528 + 438 = 24966
Step 58: 24966 + 438 = 25404
Step 59: 25404 + 438 = 25842
Step 60: 25842 + 438 = 26280
Step 61: 26280 + 438 = 26718
Step 62: 26718 + 438 = 27156
Step 63: 27156 + 438 = 27594
Step 64: 27594 + 438 = 28032
Step 65: 28032 + 438 = 28470
Step 66: 28470 + 438 = 28908
Step 67: 28908 + 438 = 29346
Step 68: 29346 + 438 = 29784
Step 69: 29784 + 438 = 30222
Step 70: 30222 + 438 = 30660
Step 71: 30660 + 438 = 31098
Step 72: 31098 + 438 = 31536
Step 73: 31536 + 438 = 31974
Step 74: 31974 + 438 = 32412
Step 75: 32412 + 438 = 32850
Step 76: 32850 + 438 = 33288
Step 77: 33288 + 438 = 33726
Step 78: 33726 + 438 = 34164
Step 79: 34164 + 438 = 34602
Step 80: 34602 + 438 = 35040
Step 81: 35040 + 438 = 35478
Step 82: 35478 + 438 = 35916
Step 83: 35916 + 438 = 36354
Step 84: 36354 + 438 = 36792
Step 85: 36792 + 438 = 37230
Step 86: 37230 + 438 = 37668
Step 87: 37668 + 438 = 38106
Step 88: 38106 + 438 = 38544
Step 89: 38544 + 438 = 38982
Step 90: 38982 + 438 = 39420
Step 91: 39420 + 438 = 39858
Step 92: 39858 + 438 = 40296
Step 93: 40296 + 438 = 40734
Step 94: 40734 + 438 = 41172
Step 95: 41172 + 438 = 41610
Step 96: 41610 + 438 = 42048
Step 97: 42048 + 438 = 42486
Step 98: 42486 + 438 = 42924
Step 99: 42924 + 438 = 43362
Step 100: 43362 + 438 = 43800
Step 101: 43800 + 438 = 44238
Step 102: 44238 + 438 = 44676
Step 103: 44676 + 438 = 45114
Step 104: 45114 + 438 = 45552
Step 105: 45552 + 438 = 45990
Step 106: 45990 + 438 = 46428
Step 107: 46428 + 438 = 46866
Step 108: 46866 + 438 = 47304
Step 109: 47304 + 438 = 47742
Step 110: 47742 + 438 = 48180
Step 111: 48180 + 438 = 48618
Step 112: 48618 + 438 = 49056
Step 113: 49056 + 438 = 49494
Step 114: 49494 + 438 = 49932
Step 115: 49932 + 438 = 50370
Step 116: 50370 + 438 = 50808
Step 117: 50808 + 438 = 51246
Step 118: 51246 + 438 = 51684
Step 119: 51684 + 438 = 52122
Step 120: 52122 + 438 = 52560
Step 121: 52560 + 438 = 52998
Step 122: 52998 + 438 = 53436
Step 123: 53436 + 438 = 53874
Step 124: 53874 + 438 = 54312
Step 125: 54312 + 438 = 54750
Step 126: 54750 + 438 = 55188
Step 127: 55188 + 438 = 55626
Step 128: 55626 + 438 = 56064
Step 129: 56064 + 438 = 56502
Step 130: 56502 + 438 = 56940
Step 131: 56940 + 438 = 57378
Step 132: 57378 + 438 = 57816
Step 133: 57816 + 438 = 58254
Step 134: 58254 + 438 = 58692
Step 135: 58692 + 438 = 59130
Step 136: 59130 + 438 = 59568
Step 137: 59568 + 438 = 60006
Step 138: 60006 + 438 = 60444
Step 139: 60444 + 438 = 60882
Step 140: 60882 + 438 = 61320
Step 141: 61320 + 438 = 61758
Step 142: 61758 + 438 = 62196
Step 143: 62196 + 438 = 62634
Step 144: 62634 + 438 = 63072
Step 145: 63072 + 438 = 63510
Step 146: 63510 + 438 = 63948
Step 147: 63948 + 438 = 64386
Step 148: 64386 + 438 = 64824
Step 149: 64824 + 438 = 65262
Step 150: 65262 + 438 = 65700
Step 151: 65700 + 438 = 66138
Step 152: 66138 + 438 = 66576
Step 153: 66576 + 438 = 67014
Step 154: 67014 + 438 = 67452
Step 155: 67452 + 438 = 67890
Step 156: 67890 + 438 = 68328
Step 157: 68328 + 438 = 68766
Step 158: 68766 + 438 = 69204
Step 159: 69204 + 438 = 69642
Step 160: 69642 + 438 = 70080
Step 161: 70080 + 438 = 70518
Step 162: 70518 + 438 = 70956
Step 163: 70956 + 438 = 71394
Step 164: 71394 + 438 = 71832
Step 165: 71832 + 438 = 72270
Step 166: 72270 + 438 = 72708

So, 438*166 = 72708