Let's roll up our sleeves and solve this. We have 331 and we're going to multiply it by 426, essentially adding 331 to itself 426 times.
Step 1: 0 + 331 = 331
Step 2: 331 + 331 = 662
Step 3: 662 + 331 = 993
Step 4: 993 + 331 = 1324
Step 5: 1324 + 331 = 1655
Step 6: 1655 + 331 = 1986
Step 7: 1986 + 331 = 2317
Step 8: 2317 + 331 = 2648
Step 9: 2648 + 331 = 2979
Step 10: 2979 + 331 = 3310
Step 11: 3310 + 331 = 3641
Step 12: 3641 + 331 = 3972
Step 13: 3972 + 331 = 4303
Step 14: 4303 + 331 = 4634
Step 15: 4634 + 331 = 4965
Step 16: 4965 + 331 = 5296
Step 17: 5296 + 331 = 5627
Step 18: 5627 + 331 = 5958
Step 19: 5958 + 331 = 6289
Step 20: 6289 + 331 = 6620
Step 21: 6620 + 331 = 6951
Step 22: 6951 + 331 = 7282
Step 23: 7282 + 331 = 7613
Step 24: 7613 + 331 = 7944
Step 25: 7944 + 331 = 8275
Step 26: 8275 + 331 = 8606
Step 27: 8606 + 331 = 8937
Step 28: 8937 + 331 = 9268
Step 29: 9268 + 331 = 9599
Step 30: 9599 + 331 = 9930
Step 31: 9930 + 331 = 10261
Step 32: 10261 + 331 = 10592
Step 33: 10592 + 331 = 10923
Step 34: 10923 + 331 = 11254
Step 35: 11254 + 331 = 11585
Step 36: 11585 + 331 = 11916
Step 37: 11916 + 331 = 12247
Step 38: 12247 + 331 = 12578
Step 39: 12578 + 331 = 12909
Step 40: 12909 + 331 = 13240
Step 41: 13240 + 331 = 13571
Step 42: 13571 + 331 = 13902
Step 43: 13902 + 331 = 14233
Step 44: 14233 + 331 = 14564
Step 45: 14564 + 331 = 14895
Step 46: 14895 + 331 = 15226
Step 47: 15226 + 331 = 15557
Step 48: 15557 + 331 = 15888
Step 49: 15888 + 331 = 16219
Step 50: 16219 + 331 = 16550
Step 51: 16550 + 331 = 16881
Step 52: 16881 + 331 = 17212
Step 53: 17212 + 331 = 17543
Step 54: 17543 + 331 = 17874
Step 55: 17874 + 331 = 18205
Step 56: 18205 + 331 = 18536
Step 57: 18536 + 331 = 18867
Step 58: 18867 + 331 = 19198
Step 59: 19198 + 331 = 19529
Step 60: 19529 + 331 = 19860
Step 61: 19860 + 331 = 20191
Step 62: 20191 + 331 = 20522
Step 63: 20522 + 331 = 20853
Step 64: 20853 + 331 = 21184
Step 65: 21184 + 331 = 21515
Step 66: 21515 + 331 = 21846
Step 67: 21846 + 331 = 22177
Step 68: 22177 + 331 = 22508
Step 69: 22508 + 331 = 22839
Step 70: 22839 + 331 = 23170
Step 71: 23170 + 331 = 23501
Step 72: 23501 + 331 = 23832
Step 73: 23832 + 331 = 24163
Step 74: 24163 + 331 = 24494
Step 75: 24494 + 331 = 24825
Step 76: 24825 + 331 = 25156
Step 77: 25156 + 331 = 25487
Step 78: 25487 + 331 = 25818
Step 79: 25818 + 331 = 26149
Step 80: 26149 + 331 = 26480
Step 81: 26480 + 331 = 26811
Step 82: 26811 + 331 = 27142
Step 83: 27142 + 331 = 27473
Step 84: 27473 + 331 = 27804
Step 85: 27804 + 331 = 28135
Step 86: 28135 + 331 = 28466
Step 87: 28466 + 331 = 28797
Step 88: 28797 + 331 = 29128
Step 89: 29128 + 331 = 29459
Step 90: 29459 + 331 = 29790
Step 91: 29790 + 331 = 30121
Step 92: 30121 + 331 = 30452
Step 93: 30452 + 331 = 30783
Step 94: 30783 + 331 = 31114
Step 95: 31114 + 331 = 31445
Step 96: 31445 + 331 = 31776
Step 97: 31776 + 331 = 32107
Step 98: 32107 + 331 = 32438
Step 99: 32438 + 331 = 32769
Step 100: 32769 + 331 = 33100
Step 101: 33100 + 331 = 33431
Step 102: 33431 + 331 = 33762
Step 103: 33762 + 331 = 34093
Step 104: 34093 + 331 = 34424
Step 105: 34424 + 331 = 34755
Step 106: 34755 + 331 = 35086
Step 107: 35086 + 331 = 35417
Step 108: 35417 + 331 = 35748
Step 109: 35748 + 331 = 36079
Step 110: 36079 + 331 = 36410
Step 111: 36410 + 331 = 36741
Step 112: 36741 + 331 = 37072
Step 113: 37072 + 331 = 37403
Step 114: 37403 + 331 = 37734
Step 115: 37734 + 331 = 38065
Step 116: 38065 + 331 = 38396
Step 117: 38396 + 331 = 38727
Step 118: 38727 + 331 = 39058
Step 119: 39058 + 331 = 39389
Step 120: 39389 + 331 = 39720
Step 121: 39720 + 331 = 40051
Step 122: 40051 + 331 = 40382
Step 123: 40382 + 331 = 40713
Step 124: 40713 + 331 = 41044
Step 125: 41044 + 331 = 41375
Step 126: 41375 + 331 = 41706
Step 127: 41706 + 331 = 42037
Step 128: 42037 + 331 = 42368
Step 129: 42368 + 331 = 42699
Step 130: 42699 + 331 = 43030
Step 131: 43030 + 331 = 43361
Step 132: 43361 + 331 = 43692
Step 133: 43692 + 331 = 44023
Step 134: 44023 + 331 = 44354
Step 135: 44354 + 331 = 44685
Step 136: 44685 + 331 = 45016
Step 137: 45016 + 331 = 45347
Step 138: 45347 + 331 = 45678
Step 139: 45678 + 331 = 46009
Step 140: 46009 + 331 = 46340
Step 141: 46340 + 331 = 46671
Step 142: 46671 + 331 = 47002
Step 143: 47002 + 331 = 47333
Step 144: 47333 + 331 = 47664
Step 145: 47664 + 331 = 47995
Step 146: 47995 + 331 = 48326
Step 147: 48326 + 331 = 48657
Step 148: 48657 + 331 = 48988
Step 149: 48988 + 331 = 49319
Step 150: 49319 + 331 = 49650
Step 151: 49650 + 331 = 49981
Step 152: 49981 + 331 = 50312
Step 153: 50312 + 331 = 50643
Step 154: 50643 + 331 = 50974
Step 155: 50974 + 331 = 51305
Step 156: 51305 + 331 = 51636
Step 157: 51636 + 331 = 51967
Step 158: 51967 + 331 = 52298
Step 159: 52298 + 331 = 52629
Step 160: 52629 + 331 = 52960
Step 161: 52960 + 331 = 53291
Step 162: 53291 + 331 = 53622
Step 163: 53622 + 331 = 53953
Step 164: 53953 + 331 = 54284
Step 165: 54284 + 331 = 54615
Step 166: 54615 + 331 = 54946
Step 167: 54946 + 331 = 55277
Step 168: 55277 + 331 = 55608
Step 169: 55608 + 331 = 55939
Step 170: 55939 + 331 = 56270
Step 171: 56270 + 331 = 56601
Step 172: 56601 + 331 = 56932
Step 173: 56932 + 331 = 57263
Step 174: 57263 + 331 = 57594
Step 175: 57594 + 331 = 57925
Step 176: 57925 + 331 = 58256
Step 177: 58256 + 331 = 58587
Step 178: 58587 + 331 = 58918
Step 179: 58918 + 331 = 59249
Step 180: 59249 + 331 = 59580
Step 181: 59580 + 331 = 59911
Step 182: 59911 + 331 = 60242
Step 183: 60242 + 331 = 60573
Step 184: 60573 + 331 = 60904
Step 185: 60904 + 331 = 61235
Step 186: 61235 + 331 = 61566
Step 187: 61566 + 331 = 61897
Step 188: 61897 + 331 = 62228
Step 189: 62228 + 331 = 62559
Step 190: 62559 + 331 = 62890
Step 191: 62890 + 331 = 63221
Step 192: 63221 + 331 = 63552
Step 193: 63552 + 331 = 63883
Step 194: 63883 + 331 = 64214
Step 195: 64214 + 331 = 64545
Step 196: 64545 + 331 = 64876
Step 197: 64876 + 331 = 65207
Step 198: 65207 + 331 = 65538
Step 199: 65538 + 331 = 65869
Step 200: 65869 + 331 = 66200
Step 201: 66200 + 331 = 66531
Step 202: 66531 + 331 = 66862
Step 203: 66862 + 331 = 67193
Step 204: 67193 + 331 = 67524
Step 205: 67524 + 331 = 67855
Step 206: 67855 + 331 = 68186
Step 207: 68186 + 331 = 68517
Step 208: 68517 + 331 = 68848
Step 209: 68848 + 331 = 69179
Step 210: 69179 + 331 = 69510
Step 211: 69510 + 331 = 69841
Step 212: 69841 + 331 = 70172
Step 213: 70172 + 331 = 70503
Step 214: 70503 + 331 = 70834
Step 215: 70834 + 331 = 71165
Step 216: 71165 + 331 = 71496
Step 217: 71496 + 331 = 71827
Step 218: 71827 + 331 = 72158
Step 219: 72158 + 331 = 72489
Step 220: 72489 + 331 = 72820
Step 221: 72820 + 331 = 73151
Step 222: 73151 + 331 = 73482
Step 223: 73482 + 331 = 73813
Step 224: 73813 + 331 = 74144
Step 225: 74144 + 331 = 74475
Step 226: 74475 + 331 = 74806
Step 227: 74806 + 331 = 75137
Step 228: 75137 + 331 = 75468
Step 229: 75468 + 331 = 75799
Step 230: 75799 + 331 = 76130
Step 231: 76130 + 331 = 76461
Step 232: 76461 + 331 = 76792
Step 233: 76792 + 331 = 77123
Step 234: 77123 + 331 = 77454
Step 235: 77454 + 331 = 77785
Step 236: 77785 + 331 = 78116
Step 237: 78116 + 331 = 78447
Step 238: 78447 + 331 = 78778
Step 239: 78778 + 331 = 79109
Step 240: 79109 + 331 = 79440
Step 241: 79440 + 331 = 79771
Step 242: 79771 + 331 = 80102
Step 243: 80102 + 331 = 80433
Step 244: 80433 + 331 = 80764
Step 245: 80764 + 331 = 81095
Step 246: 81095 + 331 = 81426
Step 247: 81426 + 331 = 81757
Step 248: 81757 + 331 = 82088
Step 249: 82088 + 331 = 82419
Step 250: 82419 + 331 = 82750
Step 251: 82750 + 331 = 83081
Step 252: 83081 + 331 = 83412
Step 253: 83412 + 331 = 83743
Step 254: 83743 + 331 = 84074
Step 255: 84074 + 331 = 84405
Step 256: 84405 + 331 = 84736
Step 257: 84736 + 331 = 85067
Step 258: 85067 + 331 = 85398
Step 259: 85398 + 331 = 85729
Step 260: 85729 + 331 = 86060
Step 261: 86060 + 331 = 86391
Step 262: 86391 + 331 = 86722
Step 263: 86722 + 331 = 87053
Step 264: 87053 + 331 = 87384
Step 265: 87384 + 331 = 87715
Step 266: 87715 + 331 = 88046
Step 267: 88046 + 331 = 88377
Step 268: 88377 + 331 = 88708
Step 269: 88708 + 331 = 89039
Step 270: 89039 + 331 = 89370
Step 271: 89370 + 331 = 89701
Step 272: 89701 + 331 = 90032
Step 273: 90032 + 331 = 90363
Step 274: 90363 + 331 = 90694
Step 275: 90694 + 331 = 91025
Step 276: 91025 + 331 = 91356
Step 277: 91356 + 331 = 91687
Step 278: 91687 + 331 = 92018
Step 279: 92018 + 331 = 92349
Step 280: 92349 + 331 = 92680
Step 281: 92680 + 331 = 93011
Step 282: 93011 + 331 = 93342
Step 283: 93342 + 331 = 93673
Step 284: 93673 + 331 = 94004
Step 285: 94004 + 331 = 94335
Step 286: 94335 + 331 = 94666
Step 287: 94666 + 331 = 94997
Step 288: 94997 + 331 = 95328
Step 289: 95328 + 331 = 95659
Step 290: 95659 + 331 = 95990
Step 291: 95990 + 331 = 96321
Step 292: 96321 + 331 = 96652
Step 293: 96652 + 331 = 96983
Step 294: 96983 + 331 = 97314
Step 295: 97314 + 331 = 97645
Step 296: 97645 + 331 = 97976
Step 297: 97976 + 331 = 98307
Step 298: 98307 + 331 = 98638
Step 299: 98638 + 331 = 98969
Step 300: 98969 + 331 = 99300
Step 301: 99300 + 331 = 99631
Step 302: 99631 + 331 = 99962
Step 303: 99962 + 331 = 100293
Step 304: 100293 + 331 = 100624
Step 305: 100624 + 331 = 100955
Step 306: 100955 + 331 = 101286
Step 307: 101286 + 331 = 101617
Step 308: 101617 + 331 = 101948
Step 309: 101948 + 331 = 102279
Step 310: 102279 + 331 = 102610
Step 311: 102610 + 331 = 102941
Step 312: 102941 + 331 = 103272
Step 313: 103272 + 331 = 103603
Step 314: 103603 + 331 = 103934
Step 315: 103934 + 331 = 104265
Step 316: 104265 + 331 = 104596
Step 317: 104596 + 331 = 104927
Step 318: 104927 + 331 = 105258
Step 319: 105258 + 331 = 105589
Step 320: 105589 + 331 = 105920
Step 321: 105920 + 331 = 106251
Step 322: 106251 + 331 = 106582
Step 323: 106582 + 331 = 106913
Step 324: 106913 + 331 = 107244
Step 325: 107244 + 331 = 107575
Step 326: 107575 + 331 = 107906
Step 327: 107906 + 331 = 108237
Step 328: 108237 + 331 = 108568
Step 329: 108568 + 331 = 108899
Step 330: 108899 + 331 = 109230
Step 331: 109230 + 331 = 109561
Step 332: 109561 + 331 = 109892
Step 333: 109892 + 331 = 110223
Step 334: 110223 + 331 = 110554
Step 335: 110554 + 331 = 110885
Step 336: 110885 + 331 = 111216
Step 337: 111216 + 331 = 111547
Step 338: 111547 + 331 = 111878
Step 339: 111878 + 331 = 112209
Step 340: 112209 + 331 = 112540
Step 341: 112540 + 331 = 112871
Step 342: 112871 + 331 = 113202
Step 343: 113202 + 331 = 113533
Step 344: 113533 + 331 = 113864
Step 345: 113864 + 331 = 114195
Step 346: 114195 + 331 = 114526
Step 347: 114526 + 331 = 114857
Step 348: 114857 + 331 = 115188
Step 349: 115188 + 331 = 115519
Step 350: 115519 + 331 = 115850
Step 351: 115850 + 331 = 116181
Step 352: 116181 + 331 = 116512
Step 353: 116512 + 331 = 116843
Step 354: 116843 + 331 = 117174
Step 355: 117174 + 331 = 117505
Step 356: 117505 + 331 = 117836
Step 357: 117836 + 331 = 118167
Step 358: 118167 + 331 = 118498
Step 359: 118498 + 331 = 118829
Step 360: 118829 + 331 = 119160
Step 361: 119160 + 331 = 119491
Step 362: 119491 + 331 = 119822
Step 363: 119822 + 331 = 120153
Step 364: 120153 + 331 = 120484
Step 365: 120484 + 331 = 120815
Step 366: 120815 + 331 = 121146
Step 367: 121146 + 331 = 121477
Step 368: 121477 + 331 = 121808
Step 369: 121808 + 331 = 122139
Step 370: 122139 + 331 = 122470
Step 371: 122470 + 331 = 122801
Step 372: 122801 + 331 = 123132
Step 373: 123132 + 331 = 123463
Step 374: 123463 + 331 = 123794
Step 375: 123794 + 331 = 124125
Step 376: 124125 + 331 = 124456
Step 377: 124456 + 331 = 124787
Step 378: 124787 + 331 = 125118
Step 379: 125118 + 331 = 125449
Step 380: 125449 + 331 = 125780
Step 381: 125780 + 331 = 126111
Step 382: 126111 + 331 = 126442
Step 383: 126442 + 331 = 126773
Step 384: 126773 + 331 = 127104
Step 385: 127104 + 331 = 127435
Step 386: 127435 + 331 = 127766
Step 387: 127766 + 331 = 128097
Step 388: 128097 + 331 = 128428
Step 389: 128428 + 331 = 128759
Step 390: 128759 + 331 = 129090
Step 391: 129090 + 331 = 129421
Step 392: 129421 + 331 = 129752
Step 393: 129752 + 331 = 130083
Step 394: 130083 + 331 = 130414
Step 395: 130414 + 331 = 130745
Step 396: 130745 + 331 = 131076
Step 397: 131076 + 331 = 131407
Step 398: 131407 + 331 = 131738
Step 399: 131738 + 331 = 132069
Step 400: 132069 + 331 = 132400
Step 401: 132400 + 331 = 132731
Step 402: 132731 + 331 = 133062
Step 403: 133062 + 331 = 133393
Step 404: 133393 + 331 = 133724
Step 405: 133724 + 331 = 134055
Step 406: 134055 + 331 = 134386
Step 407: 134386 + 331 = 134717
Step 408: 134717 + 331 = 135048
Step 409: 135048 + 331 = 135379
Step 410: 135379 + 331 = 135710
Step 411: 135710 + 331 = 136041
Step 412: 136041 + 331 = 136372
Step 413: 136372 + 331 = 136703
Step 414: 136703 + 331 = 137034
Step 415: 137034 + 331 = 137365
Step 416: 137365 + 331 = 137696
Step 417: 137696 + 331 = 138027
Step 418: 138027 + 331 = 138358
Step 419: 138358 + 331 = 138689
Step 420: 138689 + 331 = 139020
Step 421: 139020 + 331 = 139351
Step 422: 139351 + 331 = 139682
Step 423: 139682 + 331 = 140013
Step 424: 140013 + 331 = 140344
Step 425: 140344 + 331 = 140675
Step 426: 140675 + 331 = 141006

So, 331*426 = 141006