OK, let's work through this together. We're starting with 427 and we're going to multiply it by 423, which means we add 427 to itself 423 times.
Step 1: 0 + 427 = 427
Step 2: 427 + 427 = 854
Step 3: 854 + 427 = 1281
Step 4: 1281 + 427 = 1708
Step 5: 1708 + 427 = 2135
Step 6: 2135 + 427 = 2562
Step 7: 2562 + 427 = 2989
Step 8: 2989 + 427 = 3416
Step 9: 3416 + 427 = 3843
Step 10: 3843 + 427 = 4270
Step 11: 4270 + 427 = 4697
Step 12: 4697 + 427 = 5124
Step 13: 5124 + 427 = 5551
Step 14: 5551 + 427 = 5978
Step 15: 5978 + 427 = 6405
Step 16: 6405 + 427 = 6832
Step 17: 6832 + 427 = 7259
Step 18: 7259 + 427 = 7686
Step 19: 7686 + 427 = 8113
Step 20: 8113 + 427 = 8540
Step 21: 8540 + 427 = 8967
Step 22: 8967 + 427 = 9394
Step 23: 9394 + 427 = 9821
Step 24: 9821 + 427 = 10248
Step 25: 10248 + 427 = 10675
Step 26: 10675 + 427 = 11102
Step 27: 11102 + 427 = 11529
Step 28: 11529 + 427 = 11956
Step 29: 11956 + 427 = 12383
Step 30: 12383 + 427 = 12810
Step 31: 12810 + 427 = 13237
Step 32: 13237 + 427 = 13664
Step 33: 13664 + 427 = 14091
Step 34: 14091 + 427 = 14518
Step 35: 14518 + 427 = 14945
Step 36: 14945 + 427 = 15372
Step 37: 15372 + 427 = 15799
Step 38: 15799 + 427 = 16226
Step 39: 16226 + 427 = 16653
Step 40: 16653 + 427 = 17080
Step 41: 17080 + 427 = 17507
Step 42: 17507 + 427 = 17934
Step 43: 17934 + 427 = 18361
Step 44: 18361 + 427 = 18788
Step 45: 18788 + 427 = 19215
Step 46: 19215 + 427 = 19642
Step 47: 19642 + 427 = 20069
Step 48: 20069 + 427 = 20496
Step 49: 20496 + 427 = 20923
Step 50: 20923 + 427 = 21350
Step 51: 21350 + 427 = 21777
Step 52: 21777 + 427 = 22204
Step 53: 22204 + 427 = 22631
Step 54: 22631 + 427 = 23058
Step 55: 23058 + 427 = 23485
Step 56: 23485 + 427 = 23912
Step 57: 23912 + 427 = 24339
Step 58: 24339 + 427 = 24766
Step 59: 24766 + 427 = 25193
Step 60: 25193 + 427 = 25620
Step 61: 25620 + 427 = 26047
Step 62: 26047 + 427 = 26474
Step 63: 26474 + 427 = 26901
Step 64: 26901 + 427 = 27328
Step 65: 27328 + 427 = 27755
Step 66: 27755 + 427 = 28182
Step 67: 28182 + 427 = 28609
Step 68: 28609 + 427 = 29036
Step 69: 29036 + 427 = 29463
Step 70: 29463 + 427 = 29890
Step 71: 29890 + 427 = 30317
Step 72: 30317 + 427 = 30744
Step 73: 30744 + 427 = 31171
Step 74: 31171 + 427 = 31598
Step 75: 31598 + 427 = 32025
Step 76: 32025 + 427 = 32452
Step 77: 32452 + 427 = 32879
Step 78: 32879 + 427 = 33306
Step 79: 33306 + 427 = 33733
Step 80: 33733 + 427 = 34160
Step 81: 34160 + 427 = 34587
Step 82: 34587 + 427 = 35014
Step 83: 35014 + 427 = 35441
Step 84: 35441 + 427 = 35868
Step 85: 35868 + 427 = 36295
Step 86: 36295 + 427 = 36722
Step 87: 36722 + 427 = 37149
Step 88: 37149 + 427 = 37576
Step 89: 37576 + 427 = 38003
Step 90: 38003 + 427 = 38430
Step 91: 38430 + 427 = 38857
Step 92: 38857 + 427 = 39284
Step 93: 39284 + 427 = 39711
Step 94: 39711 + 427 = 40138
Step 95: 40138 + 427 = 40565
Step 96: 40565 + 427 = 40992
Step 97: 40992 + 427 = 41419
Step 98: 41419 + 427 = 41846
Step 99: 41846 + 427 = 42273
Step 100: 42273 + 427 = 42700
Step 101: 42700 + 427 = 43127
Step 102: 43127 + 427 = 43554
Step 103: 43554 + 427 = 43981
Step 104: 43981 + 427 = 44408
Step 105: 44408 + 427 = 44835
Step 106: 44835 + 427 = 45262
Step 107: 45262 + 427 = 45689
Step 108: 45689 + 427 = 46116
Step 109: 46116 + 427 = 46543
Step 110: 46543 + 427 = 46970
Step 111: 46970 + 427 = 47397
Step 112: 47397 + 427 = 47824
Step 113: 47824 + 427 = 48251
Step 114: 48251 + 427 = 48678
Step 115: 48678 + 427 = 49105
Step 116: 49105 + 427 = 49532
Step 117: 49532 + 427 = 49959
Step 118: 49959 + 427 = 50386
Step 119: 50386 + 427 = 50813
Step 120: 50813 + 427 = 51240
Step 121: 51240 + 427 = 51667
Step 122: 51667 + 427 = 52094
Step 123: 52094 + 427 = 52521
Step 124: 52521 + 427 = 52948
Step 125: 52948 + 427 = 53375
Step 126: 53375 + 427 = 53802
Step 127: 53802 + 427 = 54229
Step 128: 54229 + 427 = 54656
Step 129: 54656 + 427 = 55083
Step 130: 55083 + 427 = 55510
Step 131: 55510 + 427 = 55937
Step 132: 55937 + 427 = 56364
Step 133: 56364 + 427 = 56791
Step 134: 56791 + 427 = 57218
Step 135: 57218 + 427 = 57645
Step 136: 57645 + 427 = 58072
Step 137: 58072 + 427 = 58499
Step 138: 58499 + 427 = 58926
Step 139: 58926 + 427 = 59353
Step 140: 59353 + 427 = 59780
Step 141: 59780 + 427 = 60207
Step 142: 60207 + 427 = 60634
Step 143: 60634 + 427 = 61061
Step 144: 61061 + 427 = 61488
Step 145: 61488 + 427 = 61915
Step 146: 61915 + 427 = 62342
Step 147: 62342 + 427 = 62769
Step 148: 62769 + 427 = 63196
Step 149: 63196 + 427 = 63623
Step 150: 63623 + 427 = 64050
Step 151: 64050 + 427 = 64477
Step 152: 64477 + 427 = 64904
Step 153: 64904 + 427 = 65331
Step 154: 65331 + 427 = 65758
Step 155: 65758 + 427 = 66185
Step 156: 66185 + 427 = 66612
Step 157: 66612 + 427 = 67039
Step 158: 67039 + 427 = 67466
Step 159: 67466 + 427 = 67893
Step 160: 67893 + 427 = 68320
Step 161: 68320 + 427 = 68747
Step 162: 68747 + 427 = 69174
Step 163: 69174 + 427 = 69601
Step 164: 69601 + 427 = 70028
Step 165: 70028 + 427 = 70455
Step 166: 70455 + 427 = 70882
Step 167: 70882 + 427 = 71309
Step 168: 71309 + 427 = 71736
Step 169: 71736 + 427 = 72163
Step 170: 72163 + 427 = 72590
Step 171: 72590 + 427 = 73017
Step 172: 73017 + 427 = 73444
Step 173: 73444 + 427 = 73871
Step 174: 73871 + 427 = 74298
Step 175: 74298 + 427 = 74725
Step 176: 74725 + 427 = 75152
Step 177: 75152 + 427 = 75579
Step 178: 75579 + 427 = 76006
Step 179: 76006 + 427 = 76433
Step 180: 76433 + 427 = 76860
Step 181: 76860 + 427 = 77287
Step 182: 77287 + 427 = 77714
Step 183: 77714 + 427 = 78141
Step 184: 78141 + 427 = 78568
Step 185: 78568 + 427 = 78995
Step 186: 78995 + 427 = 79422
Step 187: 79422 + 427 = 79849
Step 188: 79849 + 427 = 80276
Step 189: 80276 + 427 = 80703
Step 190: 80703 + 427 = 81130
Step 191: 81130 + 427 = 81557
Step 192: 81557 + 427 = 81984
Step 193: 81984 + 427 = 82411
Step 194: 82411 + 427 = 82838
Step 195: 82838 + 427 = 83265
Step 196: 83265 + 427 = 83692
Step 197: 83692 + 427 = 84119
Step 198: 84119 + 427 = 84546
Step 199: 84546 + 427 = 84973
Step 200: 84973 + 427 = 85400
Step 201: 85400 + 427 = 85827
Step 202: 85827 + 427 = 86254
Step 203: 86254 + 427 = 86681
Step 204: 86681 + 427 = 87108
Step 205: 87108 + 427 = 87535
Step 206: 87535 + 427 = 87962
Step 207: 87962 + 427 = 88389
Step 208: 88389 + 427 = 88816
Step 209: 88816 + 427 = 89243
Step 210: 89243 + 427 = 89670
Step 211: 89670 + 427 = 90097
Step 212: 90097 + 427 = 90524
Step 213: 90524 + 427 = 90951
Step 214: 90951 + 427 = 91378
Step 215: 91378 + 427 = 91805
Step 216: 91805 + 427 = 92232
Step 217: 92232 + 427 = 92659
Step 218: 92659 + 427 = 93086
Step 219: 93086 + 427 = 93513
Step 220: 93513 + 427 = 93940
Step 221: 93940 + 427 = 94367
Step 222: 94367 + 427 = 94794
Step 223: 94794 + 427 = 95221
Step 224: 95221 + 427 = 95648
Step 225: 95648 + 427 = 96075
Step 226: 96075 + 427 = 96502
Step 227: 96502 + 427 = 96929
Step 228: 96929 + 427 = 97356
Step 229: 97356 + 427 = 97783
Step 230: 97783 + 427 = 98210
Step 231: 98210 + 427 = 98637
Step 232: 98637 + 427 = 99064
Step 233: 99064 + 427 = 99491
Step 234: 99491 + 427 = 99918
Step 235: 99918 + 427 = 100345
Step 236: 100345 + 427 = 100772
Step 237: 100772 + 427 = 101199
Step 238: 101199 + 427 = 101626
Step 239: 101626 + 427 = 102053
Step 240: 102053 + 427 = 102480
Step 241: 102480 + 427 = 102907
Step 242: 102907 + 427 = 103334
Step 243: 103334 + 427 = 103761
Step 244: 103761 + 427 = 104188
Step 245: 104188 + 427 = 104615
Step 246: 104615 + 427 = 105042
Step 247: 105042 + 427 = 105469
Step 248: 105469 + 427 = 105896
Step 249: 105896 + 427 = 106323
Step 250: 106323 + 427 = 106750
Step 251: 106750 + 427 = 107177
Step 252: 107177 + 427 = 107604
Step 253: 107604 + 427 = 108031
Step 254: 108031 + 427 = 108458
Step 255: 108458 + 427 = 108885
Step 256: 108885 + 427 = 109312
Step 257: 109312 + 427 = 109739
Step 258: 109739 + 427 = 110166
Step 259: 110166 + 427 = 110593
Step 260: 110593 + 427 = 111020
Step 261: 111020 + 427 = 111447
Step 262: 111447 + 427 = 111874
Step 263: 111874 + 427 = 112301
Step 264: 112301 + 427 = 112728
Step 265: 112728 + 427 = 113155
Step 266: 113155 + 427 = 113582
Step 267: 113582 + 427 = 114009
Step 268: 114009 + 427 = 114436
Step 269: 114436 + 427 = 114863
Step 270: 114863 + 427 = 115290
Step 271: 115290 + 427 = 115717
Step 272: 115717 + 427 = 116144
Step 273: 116144 + 427 = 116571
Step 274: 116571 + 427 = 116998
Step 275: 116998 + 427 = 117425
Step 276: 117425 + 427 = 117852
Step 277: 117852 + 427 = 118279
Step 278: 118279 + 427 = 118706
Step 279: 118706 + 427 = 119133
Step 280: 119133 + 427 = 119560
Step 281: 119560 + 427 = 119987
Step 282: 119987 + 427 = 120414
Step 283: 120414 + 427 = 120841
Step 284: 120841 + 427 = 121268
Step 285: 121268 + 427 = 121695
Step 286: 121695 + 427 = 122122
Step 287: 122122 + 427 = 122549
Step 288: 122549 + 427 = 122976
Step 289: 122976 + 427 = 123403
Step 290: 123403 + 427 = 123830
Step 291: 123830 + 427 = 124257
Step 292: 124257 + 427 = 124684
Step 293: 124684 + 427 = 125111
Step 294: 125111 + 427 = 125538
Step 295: 125538 + 427 = 125965
Step 296: 125965 + 427 = 126392
Step 297: 126392 + 427 = 126819
Step 298: 126819 + 427 = 127246
Step 299: 127246 + 427 = 127673
Step 300: 127673 + 427 = 128100
Step 301: 128100 + 427 = 128527
Step 302: 128527 + 427 = 128954
Step 303: 128954 + 427 = 129381
Step 304: 129381 + 427 = 129808
Step 305: 129808 + 427 = 130235
Step 306: 130235 + 427 = 130662
Step 307: 130662 + 427 = 131089
Step 308: 131089 + 427 = 131516
Step 309: 131516 + 427 = 131943
Step 310: 131943 + 427 = 132370
Step 311: 132370 + 427 = 132797
Step 312: 132797 + 427 = 133224
Step 313: 133224 + 427 = 133651
Step 314: 133651 + 427 = 134078
Step 315: 134078 + 427 = 134505
Step 316: 134505 + 427 = 134932
Step 317: 134932 + 427 = 135359
Step 318: 135359 + 427 = 135786
Step 319: 135786 + 427 = 136213
Step 320: 136213 + 427 = 136640
Step 321: 136640 + 427 = 137067
Step 322: 137067 + 427 = 137494
Step 323: 137494 + 427 = 137921
Step 324: 137921 + 427 = 138348
Step 325: 138348 + 427 = 138775
Step 326: 138775 + 427 = 139202
Step 327: 139202 + 427 = 139629
Step 328: 139629 + 427 = 140056
Step 329: 140056 + 427 = 140483
Step 330: 140483 + 427 = 140910
Step 331: 140910 + 427 = 141337
Step 332: 141337 + 427 = 141764
Step 333: 141764 + 427 = 142191
Step 334: 142191 + 427 = 142618
Step 335: 142618 + 427 = 143045
Step 336: 143045 + 427 = 143472
Step 337: 143472 + 427 = 143899
Step 338: 143899 + 427 = 144326
Step 339: 144326 + 427 = 144753
Step 340: 144753 + 427 = 145180
Step 341: 145180 + 427 = 145607
Step 342: 145607 + 427 = 146034
Step 343: 146034 + 427 = 146461
Step 344: 146461 + 427 = 146888
Step 345: 146888 + 427 = 147315
Step 346: 147315 + 427 = 147742
Step 347: 147742 + 427 = 148169
Step 348: 148169 + 427 = 148596
Step 349: 148596 + 427 = 149023
Step 350: 149023 + 427 = 149450
Step 351: 149450 + 427 = 149877
Step 352: 149877 + 427 = 150304
Step 353: 150304 + 427 = 150731
Step 354: 150731 + 427 = 151158
Step 355: 151158 + 427 = 151585
Step 356: 151585 + 427 = 152012
Step 357: 152012 + 427 = 152439
Step 358: 152439 + 427 = 152866
Step 359: 152866 + 427 = 153293
Step 360: 153293 + 427 = 153720
Step 361: 153720 + 427 = 154147
Step 362: 154147 + 427 = 154574
Step 363: 154574 + 427 = 155001
Step 364: 155001 + 427 = 155428
Step 365: 155428 + 427 = 155855
Step 366: 155855 + 427 = 156282
Step 367: 156282 + 427 = 156709
Step 368: 156709 + 427 = 157136
Step 369: 157136 + 427 = 157563
Step 370: 157563 + 427 = 157990
Step 371: 157990 + 427 = 158417
Step 372: 158417 + 427 = 158844
Step 373: 158844 + 427 = 159271
Step 374: 159271 + 427 = 159698
Step 375: 159698 + 427 = 160125
Step 376: 160125 + 427 = 160552
Step 377: 160552 + 427 = 160979
Step 378: 160979 + 427 = 161406
Step 379: 161406 + 427 = 161833
Step 380: 161833 + 427 = 162260
Step 381: 162260 + 427 = 162687
Step 382: 162687 + 427 = 163114
Step 383: 163114 + 427 = 163541
Step 384: 163541 + 427 = 163968
Step 385: 163968 + 427 = 164395
Step 386: 164395 + 427 = 164822
Step 387: 164822 + 427 = 165249
Step 388: 165249 + 427 = 165676
Step 389: 165676 + 427 = 166103
Step 390: 166103 + 427 = 166530
Step 391: 166530 + 427 = 166957
Step 392: 166957 + 427 = 167384
Step 393: 167384 + 427 = 167811
Step 394: 167811 + 427 = 168238
Step 395: 168238 + 427 = 168665
Step 396: 168665 + 427 = 169092
Step 397: 169092 + 427 = 169519
Step 398: 169519 + 427 = 169946
Step 399: 169946 + 427 = 170373
Step 400: 170373 + 427 = 170800
Step 401: 170800 + 427 = 171227
Step 402: 171227 + 427 = 171654
Step 403: 171654 + 427 = 172081
Step 404: 172081 + 427 = 172508
Step 405: 172508 + 427 = 172935
Step 406: 172935 + 427 = 173362
Step 407: 173362 + 427 = 173789
Step 408: 173789 + 427 = 174216
Step 409: 174216 + 427 = 174643
Step 410: 174643 + 427 = 175070
Step 411: 175070 + 427 = 175497
Step 412: 175497 + 427 = 175924
Step 413: 175924 + 427 = 176351
Step 414: 176351 + 427 = 176778
Step 415: 176778 + 427 = 177205
Step 416: 177205 + 427 = 177632
Step 417: 177632 + 427 = 178059
Step 418: 178059 + 427 = 178486
Step 419: 178486 + 427 = 178913
Step 420: 178913 + 427 = 179340
Step 421: 179340 + 427 = 179767
Step 422: 179767 + 427 = 180194
Step 423: 180194 + 427 = 180621

So, 427*423 = 180621