OK, let's work through this together. We're starting with 161 and we're going to multiply it by 187, which means we add 161 to itself 187 times.
Step 1: 0 + 161 = 161
Step 2: 161 + 161 = 322
Step 3: 322 + 161 = 483
Step 4: 483 + 161 = 644
Step 5: 644 + 161 = 805
Step 6: 805 + 161 = 966
Step 7: 966 + 161 = 1127
Step 8: 1127 + 161 = 1288
Step 9: 1288 + 161 = 1449
Step 10: 1449 + 161 = 1610
Step 11: 1610 + 161 = 1771
Step 12: 1771 + 161 = 1932
Step 13: 1932 + 161 = 2093
Step 14: 2093 + 161 = 2254
Step 15: 2254 + 161 = 2415
Step 16: 2415 + 161 = 2576
Step 17: 2576 + 161 = 2737
Step 18: 2737 + 161 = 2898
Step 19: 2898 + 161 = 3059
Step 20: 3059 + 161 = 3220
Step 21: 3220 + 161 = 3381
Step 22: 3381 + 161 = 3542
Step 23: 3542 + 161 = 3703
Step 24: 3703 + 161 = 3864
Step 25: 3864 + 161 = 4025
Step 26: 4025 + 161 = 4186
Step 27: 4186 + 161 = 4347
Step 28: 4347 + 161 = 4508
Step 29: 4508 + 161 = 4669
Step 30: 4669 + 161 = 4830
Step 31: 4830 + 161 = 4991
Step 32: 4991 + 161 = 5152
Step 33: 5152 + 161 = 5313
Step 34: 5313 + 161 = 5474
Step 35: 5474 + 161 = 5635
Step 36: 5635 + 161 = 5796
Step 37: 5796 + 161 = 5957
Step 38: 5957 + 161 = 6118
Step 39: 6118 + 161 = 6279
Step 40: 6279 + 161 = 6440
Step 41: 6440 + 161 = 6601
Step 42: 6601 + 161 = 6762
Step 43: 6762 + 161 = 6923
Step 44: 6923 + 161 = 7084
Step 45: 7084 + 161 = 7245
Step 46: 7245 + 161 = 7406
Step 47: 7406 + 161 = 7567
Step 48: 7567 + 161 = 7728
Step 49: 7728 + 161 = 7889
Step 50: 7889 + 161 = 8050
Step 51: 8050 + 161 = 8211
Step 52: 8211 + 161 = 8372
Step 53: 8372 + 161 = 8533
Step 54: 8533 + 161 = 8694
Step 55: 8694 + 161 = 8855
Step 56: 8855 + 161 = 9016
Step 57: 9016 + 161 = 9177
Step 58: 9177 + 161 = 9338
Step 59: 9338 + 161 = 9499
Step 60: 9499 + 161 = 9660
Step 61: 9660 + 161 = 9821
Step 62: 9821 + 161 = 9982
Step 63: 9982 + 161 = 10143
Step 64: 10143 + 161 = 10304
Step 65: 10304 + 161 = 10465
Step 66: 10465 + 161 = 10626
Step 67: 10626 + 161 = 10787
Step 68: 10787 + 161 = 10948
Step 69: 10948 + 161 = 11109
Step 70: 11109 + 161 = 11270
Step 71: 11270 + 161 = 11431
Step 72: 11431 + 161 = 11592
Step 73: 11592 + 161 = 11753
Step 74: 11753 + 161 = 11914
Step 75: 11914 + 161 = 12075
Step 76: 12075 + 161 = 12236
Step 77: 12236 + 161 = 12397
Step 78: 12397 + 161 = 12558
Step 79: 12558 + 161 = 12719
Step 80: 12719 + 161 = 12880
Step 81: 12880 + 161 = 13041
Step 82: 13041 + 161 = 13202
Step 83: 13202 + 161 = 13363
Step 84: 13363 + 161 = 13524
Step 85: 13524 + 161 = 13685
Step 86: 13685 + 161 = 13846
Step 87: 13846 + 161 = 14007
Step 88: 14007 + 161 = 14168
Step 89: 14168 + 161 = 14329
Step 90: 14329 + 161 = 14490
Step 91: 14490 + 161 = 14651
Step 92: 14651 + 161 = 14812
Step 93: 14812 + 161 = 14973
Step 94: 14973 + 161 = 15134
Step 95: 15134 + 161 = 15295
Step 96: 15295 + 161 = 15456
Step 97: 15456 + 161 = 15617
Step 98: 15617 + 161 = 15778
Step 99: 15778 + 161 = 15939
Step 100: 15939 + 161 = 16100
Step 101: 16100 + 161 = 16261
Step 102: 16261 + 161 = 16422
Step 103: 16422 + 161 = 16583
Step 104: 16583 + 161 = 16744
Step 105: 16744 + 161 = 16905
Step 106: 16905 + 161 = 17066
Step 107: 17066 + 161 = 17227
Step 108: 17227 + 161 = 17388
Step 109: 17388 + 161 = 17549
Step 110: 17549 + 161 = 17710
Step 111: 17710 + 161 = 17871
Step 112: 17871 + 161 = 18032
Step 113: 18032 + 161 = 18193
Step 114: 18193 + 161 = 18354
Step 115: 18354 + 161 = 18515
Step 116: 18515 + 161 = 18676
Step 117: 18676 + 161 = 18837
Step 118: 18837 + 161 = 18998
Step 119: 18998 + 161 = 19159
Step 120: 19159 + 161 = 19320
Step 121: 19320 + 161 = 19481
Step 122: 19481 + 161 = 19642
Step 123: 19642 + 161 = 19803
Step 124: 19803 + 161 = 19964
Step 125: 19964 + 161 = 20125
Step 126: 20125 + 161 = 20286
Step 127: 20286 + 161 = 20447
Step 128: 20447 + 161 = 20608
Step 129: 20608 + 161 = 20769
Step 130: 20769 + 161 = 20930
Step 131: 20930 + 161 = 21091
Step 132: 21091 + 161 = 21252
Step 133: 21252 + 161 = 21413
Step 134: 21413 + 161 = 21574
Step 135: 21574 + 161 = 21735
Step 136: 21735 + 161 = 21896
Step 137: 21896 + 161 = 22057
Step 138: 22057 + 161 = 22218
Step 139: 22218 + 161 = 22379
Step 140: 22379 + 161 = 22540
Step 141: 22540 + 161 = 22701
Step 142: 22701 + 161 = 22862
Step 143: 22862 + 161 = 23023
Step 144: 23023 + 161 = 23184
Step 145: 23184 + 161 = 23345
Step 146: 23345 + 161 = 23506
Step 147: 23506 + 161 = 23667
Step 148: 23667 + 161 = 23828
Step 149: 23828 + 161 = 23989
Step 150: 23989 + 161 = 24150
Step 151: 24150 + 161 = 24311
Step 152: 24311 + 161 = 24472
Step 153: 24472 + 161 = 24633
Step 154: 24633 + 161 = 24794
Step 155: 24794 + 161 = 24955
Step 156: 24955 + 161 = 25116
Step 157: 25116 + 161 = 25277
Step 158: 25277 + 161 = 25438
Step 159: 25438 + 161 = 25599
Step 160: 25599 + 161 = 25760
Step 161: 25760 + 161 = 25921
Step 162: 25921 + 161 = 26082
Step 163: 26082 + 161 = 26243
Step 164: 26243 + 161 = 26404
Step 165: 26404 + 161 = 26565
Step 166: 26565 + 161 = 26726
Step 167: 26726 + 161 = 26887
Step 168: 26887 + 161 = 27048
Step 169: 27048 + 161 = 27209
Step 170: 27209 + 161 = 27370
Step 171: 27370 + 161 = 27531
Step 172: 27531 + 161 = 27692
Step 173: 27692 + 161 = 27853
Step 174: 27853 + 161 = 28014
Step 175: 28014 + 161 = 28175
Step 176: 28175 + 161 = 28336
Step 177: 28336 + 161 = 28497
Step 178: 28497 + 161 = 28658
Step 179: 28658 + 161 = 28819
Step 180: 28819 + 161 = 28980
Step 181: 28980 + 161 = 29141
Step 182: 29141 + 161 = 29302
Step 183: 29302 + 161 = 29463
Step 184: 29463 + 161 = 29624
Step 185: 29624 + 161 = 29785
Step 186: 29785 + 161 = 29946
Step 187: 29946 + 161 = 30107

So, 161*187 = 30107