Sure thing, let's get straight to it. We start with 403 and we're going to multiply it by 161, which means adding 403 to itself 161 times.
Step 1: 0 + 403 = 403
Step 2: 403 + 403 = 806
Step 3: 806 + 403 = 1209
Step 4: 1209 + 403 = 1612
Step 5: 1612 + 403 = 2015
Step 6: 2015 + 403 = 2418
Step 7: 2418 + 403 = 2821
Step 8: 2821 + 403 = 3224
Step 9: 3224 + 403 = 3627
Step 10: 3627 + 403 = 4030
Step 11: 4030 + 403 = 4433
Step 12: 4433 + 403 = 4836
Step 13: 4836 + 403 = 5239
Step 14: 5239 + 403 = 5642
Step 15: 5642 + 403 = 6045
Step 16: 6045 + 403 = 6448
Step 17: 6448 + 403 = 6851
Step 18: 6851 + 403 = 7254
Step 19: 7254 + 403 = 7657
Step 20: 7657 + 403 = 8060
Step 21: 8060 + 403 = 8463
Step 22: 8463 + 403 = 8866
Step 23: 8866 + 403 = 9269
Step 24: 9269 + 403 = 9672
Step 25: 9672 + 403 = 10075
Step 26: 10075 + 403 = 10478
Step 27: 10478 + 403 = 10881
Step 28: 10881 + 403 = 11284
Step 29: 11284 + 403 = 11687
Step 30: 11687 + 403 = 12090
Step 31: 12090 + 403 = 12493
Step 32: 12493 + 403 = 12896
Step 33: 12896 + 403 = 13299
Step 34: 13299 + 403 = 13702
Step 35: 13702 + 403 = 14105
Step 36: 14105 + 403 = 14508
Step 37: 14508 + 403 = 14911
Step 38: 14911 + 403 = 15314
Step 39: 15314 + 403 = 15717
Step 40: 15717 + 403 = 16120
Step 41: 16120 + 403 = 16523
Step 42: 16523 + 403 = 16926
Step 43: 16926 + 403 = 17329
Step 44: 17329 + 403 = 17732
Step 45: 17732 + 403 = 18135
Step 46: 18135 + 403 = 18538
Step 47: 18538 + 403 = 18941
Step 48: 18941 + 403 = 19344
Step 49: 19344 + 403 = 19747
Step 50: 19747 + 403 = 20150
Step 51: 20150 + 403 = 20553
Step 52: 20553 + 403 = 20956
Step 53: 20956 + 403 = 21359
Step 54: 21359 + 403 = 21762
Step 55: 21762 + 403 = 22165
Step 56: 22165 + 403 = 22568
Step 57: 22568 + 403 = 22971
Step 58: 22971 + 403 = 23374
Step 59: 23374 + 403 = 23777
Step 60: 23777 + 403 = 24180
Step 61: 24180 + 403 = 24583
Step 62: 24583 + 403 = 24986
Step 63: 24986 + 403 = 25389
Step 64: 25389 + 403 = 25792
Step 65: 25792 + 403 = 26195
Step 66: 26195 + 403 = 26598
Step 67: 26598 + 403 = 27001
Step 68: 27001 + 403 = 27404
Step 69: 27404 + 403 = 27807
Step 70: 27807 + 403 = 28210
Step 71: 28210 + 403 = 28613
Step 72: 28613 + 403 = 29016
Step 73: 29016 + 403 = 29419
Step 74: 29419 + 403 = 29822
Step 75: 29822 + 403 = 30225
Step 76: 30225 + 403 = 30628
Step 77: 30628 + 403 = 31031
Step 78: 31031 + 403 = 31434
Step 79: 31434 + 403 = 31837
Step 80: 31837 + 403 = 32240
Step 81: 32240 + 403 = 32643
Step 82: 32643 + 403 = 33046
Step 83: 33046 + 403 = 33449
Step 84: 33449 + 403 = 33852
Step 85: 33852 + 403 = 34255
Step 86: 34255 + 403 = 34658
Step 87: 34658 + 403 = 35061
Step 88: 35061 + 403 = 35464
Step 89: 35464 + 403 = 35867
Step 90: 35867 + 403 = 36270
Step 91: 36270 + 403 = 36673
Step 92: 36673 + 403 = 37076
Step 93: 37076 + 403 = 37479
Step 94: 37479 + 403 = 37882
Step 95: 37882 + 403 = 38285
Step 96: 38285 + 403 = 38688
Step 97: 38688 + 403 = 39091
Step 98: 39091 + 403 = 39494
Step 99: 39494 + 403 = 39897
Step 100: 39897 + 403 = 40300
Step 101: 40300 + 403 = 40703
Step 102: 40703 + 403 = 41106
Step 103: 41106 + 403 = 41509
Step 104: 41509 + 403 = 41912
Step 105: 41912 + 403 = 42315
Step 106: 42315 + 403 = 42718
Step 107: 42718 + 403 = 43121
Step 108: 43121 + 403 = 43524
Step 109: 43524 + 403 = 43927
Step 110: 43927 + 403 = 44330
Step 111: 44330 + 403 = 44733
Step 112: 44733 + 403 = 45136
Step 113: 45136 + 403 = 45539
Step 114: 45539 + 403 = 45942
Step 115: 45942 + 403 = 46345
Step 116: 46345 + 403 = 46748
Step 117: 46748 + 403 = 47151
Step 118: 47151 + 403 = 47554
Step 119: 47554 + 403 = 47957
Step 120: 47957 + 403 = 48360
Step 121: 48360 + 403 = 48763
Step 122: 48763 + 403 = 49166
Step 123: 49166 + 403 = 49569
Step 124: 49569 + 403 = 49972
Step 125: 49972 + 403 = 50375
Step 126: 50375 + 403 = 50778
Step 127: 50778 + 403 = 51181
Step 128: 51181 + 403 = 51584
Step 129: 51584 + 403 = 51987
Step 130: 51987 + 403 = 52390
Step 131: 52390 + 403 = 52793
Step 132: 52793 + 403 = 53196
Step 133: 53196 + 403 = 53599
Step 134: 53599 + 403 = 54002
Step 135: 54002 + 403 = 54405
Step 136: 54405 + 403 = 54808
Step 137: 54808 + 403 = 55211
Step 138: 55211 + 403 = 55614
Step 139: 55614 + 403 = 56017
Step 140: 56017 + 403 = 56420
Step 141: 56420 + 403 = 56823
Step 142: 56823 + 403 = 57226
Step 143: 57226 + 403 = 57629
Step 144: 57629 + 403 = 58032
Step 145: 58032 + 403 = 58435
Step 146: 58435 + 403 = 58838
Step 147: 58838 + 403 = 59241
Step 148: 59241 + 403 = 59644
Step 149: 59644 + 403 = 60047
Step 150: 60047 + 403 = 60450
Step 151: 60450 + 403 = 60853
Step 152: 60853 + 403 = 61256
Step 153: 61256 + 403 = 61659
Step 154: 61659 + 403 = 62062
Step 155: 62062 + 403 = 62465
Step 156: 62465 + 403 = 62868
Step 157: 62868 + 403 = 63271
Step 158: 63271 + 403 = 63674
Step 159: 63674 + 403 = 64077
Step 160: 64077 + 403 = 64480
Step 161: 64480 + 403 = 64883

So, 403*161 = 64883