OK, let's crack this. We're given 99 and our task is to multiply it by 426. Essentially, we'll be adding 99 to itself 426 times.
Step 1: 0 + 99 = 99
Step 2: 99 + 99 = 198
Step 3: 198 + 99 = 297
Step 4: 297 + 99 = 396
Step 5: 396 + 99 = 495
Step 6: 495 + 99 = 594
Step 7: 594 + 99 = 693
Step 8: 693 + 99 = 792
Step 9: 792 + 99 = 891
Step 10: 891 + 99 = 990
Step 11: 990 + 99 = 1089
Step 12: 1089 + 99 = 1188
Step 13: 1188 + 99 = 1287
Step 14: 1287 + 99 = 1386
Step 15: 1386 + 99 = 1485
Step 16: 1485 + 99 = 1584
Step 17: 1584 + 99 = 1683
Step 18: 1683 + 99 = 1782
Step 19: 1782 + 99 = 1881
Step 20: 1881 + 99 = 1980
Step 21: 1980 + 99 = 2079
Step 22: 2079 + 99 = 2178
Step 23: 2178 + 99 = 2277
Step 24: 2277 + 99 = 2376
Step 25: 2376 + 99 = 2475
Step 26: 2475 + 99 = 2574
Step 27: 2574 + 99 = 2673
Step 28: 2673 + 99 = 2772
Step 29: 2772 + 99 = 2871
Step 30: 2871 + 99 = 2970
Step 31: 2970 + 99 = 3069
Step 32: 3069 + 99 = 3168
Step 33: 3168 + 99 = 3267
Step 34: 3267 + 99 = 3366
Step 35: 3366 + 99 = 3465
Step 36: 3465 + 99 = 3564
Step 37: 3564 + 99 = 3663
Step 38: 3663 + 99 = 3762
Step 39: 3762 + 99 = 3861
Step 40: 3861 + 99 = 3960
Step 41: 3960 + 99 = 4059
Step 42: 4059 + 99 = 4158
Step 43: 4158 + 99 = 4257
Step 44: 4257 + 99 = 4356
Step 45: 4356 + 99 = 4455
Step 46: 4455 + 99 = 4554
Step 47: 4554 + 99 = 4653
Step 48: 4653 + 99 = 4752
Step 49: 4752 + 99 = 4851
Step 50: 4851 + 99 = 4950
Step 51: 4950 + 99 = 5049
Step 52: 5049 + 99 = 5148
Step 53: 5148 + 99 = 5247
Step 54: 5247 + 99 = 5346
Step 55: 5346 + 99 = 5445
Step 56: 5445 + 99 = 5544
Step 57: 5544 + 99 = 5643
Step 58: 5643 + 99 = 5742
Step 59: 5742 + 99 = 5841
Step 60: 5841 + 99 = 5940
Step 61: 5940 + 99 = 6039
Step 62: 6039 + 99 = 6138
Step 63: 6138 + 99 = 6237
Step 64: 6237 + 99 = 6336
Step 65: 6336 + 99 = 6435
Step 66: 6435 + 99 = 6534
Step 67: 6534 + 99 = 6633
Step 68: 6633 + 99 = 6732
Step 69: 6732 + 99 = 6831
Step 70: 6831 + 99 = 6930
Step 71: 6930 + 99 = 7029
Step 72: 7029 + 99 = 7128
Step 73: 7128 + 99 = 7227
Step 74: 7227 + 99 = 7326
Step 75: 7326 + 99 = 7425
Step 76: 7425 + 99 = 7524
Step 77: 7524 + 99 = 7623
Step 78: 7623 + 99 = 7722
Step 79: 7722 + 99 = 7821
Step 80: 7821 + 99 = 7920
Step 81: 7920 + 99 = 8019
Step 82: 8019 + 99 = 8118
Step 83: 8118 + 99 = 8217
Step 84: 8217 + 99 = 8316
Step 85: 8316 + 99 = 8415
Step 86: 8415 + 99 = 8514
Step 87: 8514 + 99 = 8613
Step 88: 8613 + 99 = 8712
Step 89: 8712 + 99 = 8811
Step 90: 8811 + 99 = 8910
Step 91: 8910 + 99 = 9009
Step 92: 9009 + 99 = 9108
Step 93: 9108 + 99 = 9207
Step 94: 9207 + 99 = 9306
Step 95: 9306 + 99 = 9405
Step 96: 9405 + 99 = 9504
Step 97: 9504 + 99 = 9603
Step 98: 9603 + 99 = 9702
Step 99: 9702 + 99 = 9801
Step 100: 9801 + 99 = 9900
Step 101: 9900 + 99 = 9999
Step 102: 9999 + 99 = 10098
Step 103: 10098 + 99 = 10197
Step 104: 10197 + 99 = 10296
Step 105: 10296 + 99 = 10395
Step 106: 10395 + 99 = 10494
Step 107: 10494 + 99 = 10593
Step 108: 10593 + 99 = 10692
Step 109: 10692 + 99 = 10791
Step 110: 10791 + 99 = 10890
Step 111: 10890 + 99 = 10989
Step 112: 10989 + 99 = 11088
Step 113: 11088 + 99 = 11187
Step 114: 11187 + 99 = 11286
Step 115: 11286 + 99 = 11385
Step 116: 11385 + 99 = 11484
Step 117: 11484 + 99 = 11583
Step 118: 11583 + 99 = 11682
Step 119: 11682 + 99 = 11781
Step 120: 11781 + 99 = 11880
Step 121: 11880 + 99 = 11979
Step 122: 11979 + 99 = 12078
Step 123: 12078 + 99 = 12177
Step 124: 12177 + 99 = 12276
Step 125: 12276 + 99 = 12375
Step 126: 12375 + 99 = 12474
Step 127: 12474 + 99 = 12573
Step 128: 12573 + 99 = 12672
Step 129: 12672 + 99 = 12771
Step 130: 12771 + 99 = 12870
Step 131: 12870 + 99 = 12969
Step 132: 12969 + 99 = 13068
Step 133: 13068 + 99 = 13167
Step 134: 13167 + 99 = 13266
Step 135: 13266 + 99 = 13365
Step 136: 13365 + 99 = 13464
Step 137: 13464 + 99 = 13563
Step 138: 13563 + 99 = 13662
Step 139: 13662 + 99 = 13761
Step 140: 13761 + 99 = 13860
Step 141: 13860 + 99 = 13959
Step 142: 13959 + 99 = 14058
Step 143: 14058 + 99 = 14157
Step 144: 14157 + 99 = 14256
Step 145: 14256 + 99 = 14355
Step 146: 14355 + 99 = 14454
Step 147: 14454 + 99 = 14553
Step 148: 14553 + 99 = 14652
Step 149: 14652 + 99 = 14751
Step 150: 14751 + 99 = 14850
Step 151: 14850 + 99 = 14949
Step 152: 14949 + 99 = 15048
Step 153: 15048 + 99 = 15147
Step 154: 15147 + 99 = 15246
Step 155: 15246 + 99 = 15345
Step 156: 15345 + 99 = 15444
Step 157: 15444 + 99 = 15543
Step 158: 15543 + 99 = 15642
Step 159: 15642 + 99 = 15741
Step 160: 15741 + 99 = 15840
Step 161: 15840 + 99 = 15939
Step 162: 15939 + 99 = 16038
Step 163: 16038 + 99 = 16137
Step 164: 16137 + 99 = 16236
Step 165: 16236 + 99 = 16335
Step 166: 16335 + 99 = 16434
Step 167: 16434 + 99 = 16533
Step 168: 16533 + 99 = 16632
Step 169: 16632 + 99 = 16731
Step 170: 16731 + 99 = 16830
Step 171: 16830 + 99 = 16929
Step 172: 16929 + 99 = 17028
Step 173: 17028 + 99 = 17127
Step 174: 17127 + 99 = 17226
Step 175: 17226 + 99 = 17325
Step 176: 17325 + 99 = 17424
Step 177: 17424 + 99 = 17523
Step 178: 17523 + 99 = 17622
Step 179: 17622 + 99 = 17721
Step 180: 17721 + 99 = 17820
Step 181: 17820 + 99 = 17919
Step 182: 17919 + 99 = 18018
Step 183: 18018 + 99 = 18117
Step 184: 18117 + 99 = 18216
Step 185: 18216 + 99 = 18315
Step 186: 18315 + 99 = 18414
Step 187: 18414 + 99 = 18513
Step 188: 18513 + 99 = 18612
Step 189: 18612 + 99 = 18711
Step 190: 18711 + 99 = 18810
Step 191: 18810 + 99 = 18909
Step 192: 18909 + 99 = 19008
Step 193: 19008 + 99 = 19107
Step 194: 19107 + 99 = 19206
Step 195: 19206 + 99 = 19305
Step 196: 19305 + 99 = 19404
Step 197: 19404 + 99 = 19503
Step 198: 19503 + 99 = 19602
Step 199: 19602 + 99 = 19701
Step 200: 19701 + 99 = 19800
Step 201: 19800 + 99 = 19899
Step 202: 19899 + 99 = 19998
Step 203: 19998 + 99 = 20097
Step 204: 20097 + 99 = 20196
Step 205: 20196 + 99 = 20295
Step 206: 20295 + 99 = 20394
Step 207: 20394 + 99 = 20493
Step 208: 20493 + 99 = 20592
Step 209: 20592 + 99 = 20691
Step 210: 20691 + 99 = 20790
Step 211: 20790 + 99 = 20889
Step 212: 20889 + 99 = 20988
Step 213: 20988 + 99 = 21087
Step 214: 21087 + 99 = 21186
Step 215: 21186 + 99 = 21285
Step 216: 21285 + 99 = 21384
Step 217: 21384 + 99 = 21483
Step 218: 21483 + 99 = 21582
Step 219: 21582 + 99 = 21681
Step 220: 21681 + 99 = 21780
Step 221: 21780 + 99 = 21879
Step 222: 21879 + 99 = 21978
Step 223: 21978 + 99 = 22077
Step 224: 22077 + 99 = 22176
Step 225: 22176 + 99 = 22275
Step 226: 22275 + 99 = 22374
Step 227: 22374 + 99 = 22473
Step 228: 22473 + 99 = 22572
Step 229: 22572 + 99 = 22671
Step 230: 22671 + 99 = 22770
Step 231: 22770 + 99 = 22869
Step 232: 22869 + 99 = 22968
Step 233: 22968 + 99 = 23067
Step 234: 23067 + 99 = 23166
Step 235: 23166 + 99 = 23265
Step 236: 23265 + 99 = 23364
Step 237: 23364 + 99 = 23463
Step 238: 23463 + 99 = 23562
Step 239: 23562 + 99 = 23661
Step 240: 23661 + 99 = 23760
Step 241: 23760 + 99 = 23859
Step 242: 23859 + 99 = 23958
Step 243: 23958 + 99 = 24057
Step 244: 24057 + 99 = 24156
Step 245: 24156 + 99 = 24255
Step 246: 24255 + 99 = 24354
Step 247: 24354 + 99 = 24453
Step 248: 24453 + 99 = 24552
Step 249: 24552 + 99 = 24651
Step 250: 24651 + 99 = 24750
Step 251: 24750 + 99 = 24849
Step 252: 24849 + 99 = 24948
Step 253: 24948 + 99 = 25047
Step 254: 25047 + 99 = 25146
Step 255: 25146 + 99 = 25245
Step 256: 25245 + 99 = 25344
Step 257: 25344 + 99 = 25443
Step 258: 25443 + 99 = 25542
Step 259: 25542 + 99 = 25641
Step 260: 25641 + 99 = 25740
Step 261: 25740 + 99 = 25839
Step 262: 25839 + 99 = 25938
Step 263: 25938 + 99 = 26037
Step 264: 26037 + 99 = 26136
Step 265: 26136 + 99 = 26235
Step 266: 26235 + 99 = 26334
Step 267: 26334 + 99 = 26433
Step 268: 26433 + 99 = 26532
Step 269: 26532 + 99 = 26631
Step 270: 26631 + 99 = 26730
Step 271: 26730 + 99 = 26829
Step 272: 26829 + 99 = 26928
Step 273: 26928 + 99 = 27027
Step 274: 27027 + 99 = 27126
Step 275: 27126 + 99 = 27225
Step 276: 27225 + 99 = 27324
Step 277: 27324 + 99 = 27423
Step 278: 27423 + 99 = 27522
Step 279: 27522 + 99 = 27621
Step 280: 27621 + 99 = 27720
Step 281: 27720 + 99 = 27819
Step 282: 27819 + 99 = 27918
Step 283: 27918 + 99 = 28017
Step 284: 28017 + 99 = 28116
Step 285: 28116 + 99 = 28215
Step 286: 28215 + 99 = 28314
Step 287: 28314 + 99 = 28413
Step 288: 28413 + 99 = 28512
Step 289: 28512 + 99 = 28611
Step 290: 28611 + 99 = 28710
Step 291: 28710 + 99 = 28809
Step 292: 28809 + 99 = 28908
Step 293: 28908 + 99 = 29007
Step 294: 29007 + 99 = 29106
Step 295: 29106 + 99 = 29205
Step 296: 29205 + 99 = 29304
Step 297: 29304 + 99 = 29403
Step 298: 29403 + 99 = 29502
Step 299: 29502 + 99 = 29601
Step 300: 29601 + 99 = 29700
Step 301: 29700 + 99 = 29799
Step 302: 29799 + 99 = 29898
Step 303: 29898 + 99 = 29997
Step 304: 29997 + 99 = 30096
Step 305: 30096 + 99 = 30195
Step 306: 30195 + 99 = 30294
Step 307: 30294 + 99 = 30393
Step 308: 30393 + 99 = 30492
Step 309: 30492 + 99 = 30591
Step 310: 30591 + 99 = 30690
Step 311: 30690 + 99 = 30789
Step 312: 30789 + 99 = 30888
Step 313: 30888 + 99 = 30987
Step 314: 30987 + 99 = 31086
Step 315: 31086 + 99 = 31185
Step 316: 31185 + 99 = 31284
Step 317: 31284 + 99 = 31383
Step 318: 31383 + 99 = 31482
Step 319: 31482 + 99 = 31581
Step 320: 31581 + 99 = 31680
Step 321: 31680 + 99 = 31779
Step 322: 31779 + 99 = 31878
Step 323: 31878 + 99 = 31977
Step 324: 31977 + 99 = 32076
Step 325: 32076 + 99 = 32175
Step 326: 32175 + 99 = 32274
Step 327: 32274 + 99 = 32373
Step 328: 32373 + 99 = 32472
Step 329: 32472 + 99 = 32571
Step 330: 32571 + 99 = 32670
Step 331: 32670 + 99 = 32769
Step 332: 32769 + 99 = 32868
Step 333: 32868 + 99 = 32967
Step 334: 32967 + 99 = 33066
Step 335: 33066 + 99 = 33165
Step 336: 33165 + 99 = 33264
Step 337: 33264 + 99 = 33363
Step 338: 33363 + 99 = 33462
Step 339: 33462 + 99 = 33561
Step 340: 33561 + 99 = 33660
Step 341: 33660 + 99 = 33759
Step 342: 33759 + 99 = 33858
Step 343: 33858 + 99 = 33957
Step 344: 33957 + 99 = 34056
Step 345: 34056 + 99 = 34155
Step 346: 34155 + 99 = 34254
Step 347: 34254 + 99 = 34353
Step 348: 34353 + 99 = 34452
Step 349: 34452 + 99 = 34551
Step 350: 34551 + 99 = 34650
Step 351: 34650 + 99 = 34749
Step 352: 34749 + 99 = 34848
Step 353: 34848 + 99 = 34947
Step 354: 34947 + 99 = 35046
Step 355: 35046 + 99 = 35145
Step 356: 35145 + 99 = 35244
Step 357: 35244 + 99 = 35343
Step 358: 35343 + 99 = 35442
Step 359: 35442 + 99 = 35541
Step 360: 35541 + 99 = 35640
Step 361: 35640 + 99 = 35739
Step 362: 35739 + 99 = 35838
Step 363: 35838 + 99 = 35937
Step 364: 35937 + 99 = 36036
Step 365: 36036 + 99 = 36135
Step 366: 36135 + 99 = 36234
Step 367: 36234 + 99 = 36333
Step 368: 36333 + 99 = 36432
Step 369: 36432 + 99 = 36531
Step 370: 36531 + 99 = 36630
Step 371: 36630 + 99 = 36729
Step 372: 36729 + 99 = 36828
Step 373: 36828 + 99 = 36927
Step 374: 36927 + 99 = 37026
Step 375: 37026 + 99 = 37125
Step 376: 37125 + 99 = 37224
Step 377: 37224 + 99 = 37323
Step 378: 37323 + 99 = 37422
Step 379: 37422 + 99 = 37521
Step 380: 37521 + 99 = 37620
Step 381: 37620 + 99 = 37719
Step 382: 37719 + 99 = 37818
Step 383: 37818 + 99 = 37917
Step 384: 37917 + 99 = 38016
Step 385: 38016 + 99 = 38115
Step 386: 38115 + 99 = 38214
Step 387: 38214 + 99 = 38313
Step 388: 38313 + 99 = 38412
Step 389: 38412 + 99 = 38511
Step 390: 38511 + 99 = 38610
Step 391: 38610 + 99 = 38709
Step 392: 38709 + 99 = 38808
Step 393: 38808 + 99 = 38907
Step 394: 38907 + 99 = 39006
Step 395: 39006 + 99 = 39105
Step 396: 39105 + 99 = 39204
Step 397: 39204 + 99 = 39303
Step 398: 39303 + 99 = 39402
Step 399: 39402 + 99 = 39501
Step 400: 39501 + 99 = 39600
Step 401: 39600 + 99 = 39699
Step 402: 39699 + 99 = 39798
Step 403: 39798 + 99 = 39897
Step 404: 39897 + 99 = 39996
Step 405: 39996 + 99 = 40095
Step 406: 40095 + 99 = 40194
Step 407: 40194 + 99 = 40293
Step 408: 40293 + 99 = 40392
Step 409: 40392 + 99 = 40491
Step 410: 40491 + 99 = 40590
Step 411: 40590 + 99 = 40689
Step 412: 40689 + 99 = 40788
Step 413: 40788 + 99 = 40887
Step 414: 40887 + 99 = 40986
Step 415: 40986 + 99 = 41085
Step 416: 41085 + 99 = 41184
Step 417: 41184 + 99 = 41283
Step 418: 41283 + 99 = 41382
Step 419: 41382 + 99 = 41481
Step 420: 41481 + 99 = 41580
Step 421: 41580 + 99 = 41679
Step 422: 41679 + 99 = 41778
Step 423: 41778 + 99 = 41877
Step 424: 41877 + 99 = 41976
Step 425: 41976 + 99 = 42075
Step 426: 42075 + 99 = 42174

So, 99*426 = 42174