Alright, let's solve this math problem step by step. First, we have the number 621. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 408. So, we're going to take the number 621 and add it to itself 408 times.
Step 1: 0 + 621 = 621
Step 2: 621 + 621 = 1242
Step 3: 1242 + 621 = 1863
Step 4: 1863 + 621 = 2484
Step 5: 2484 + 621 = 3105
Step 6: 3105 + 621 = 3726
Step 7: 3726 + 621 = 4347
Step 8: 4347 + 621 = 4968
Step 9: 4968 + 621 = 5589
Step 10: 5589 + 621 = 6210
Step 11: 6210 + 621 = 6831
Step 12: 6831 + 621 = 7452
Step 13: 7452 + 621 = 8073
Step 14: 8073 + 621 = 8694
Step 15: 8694 + 621 = 9315
Step 16: 9315 + 621 = 9936
Step 17: 9936 + 621 = 10557
Step 18: 10557 + 621 = 11178
Step 19: 11178 + 621 = 11799
Step 20: 11799 + 621 = 12420
Step 21: 12420 + 621 = 13041
Step 22: 13041 + 621 = 13662
Step 23: 13662 + 621 = 14283
Step 24: 14283 + 621 = 14904
Step 25: 14904 + 621 = 15525
Step 26: 15525 + 621 = 16146
Step 27: 16146 + 621 = 16767
Step 28: 16767 + 621 = 17388
Step 29: 17388 + 621 = 18009
Step 30: 18009 + 621 = 18630
Step 31: 18630 + 621 = 19251
Step 32: 19251 + 621 = 19872
Step 33: 19872 + 621 = 20493
Step 34: 20493 + 621 = 21114
Step 35: 21114 + 621 = 21735
Step 36: 21735 + 621 = 22356
Step 37: 22356 + 621 = 22977
Step 38: 22977 + 621 = 23598
Step 39: 23598 + 621 = 24219
Step 40: 24219 + 621 = 24840
Step 41: 24840 + 621 = 25461
Step 42: 25461 + 621 = 26082
Step 43: 26082 + 621 = 26703
Step 44: 26703 + 621 = 27324
Step 45: 27324 + 621 = 27945
Step 46: 27945 + 621 = 28566
Step 47: 28566 + 621 = 29187
Step 48: 29187 + 621 = 29808
Step 49: 29808 + 621 = 30429
Step 50: 30429 + 621 = 31050
Step 51: 31050 + 621 = 31671
Step 52: 31671 + 621 = 32292
Step 53: 32292 + 621 = 32913
Step 54: 32913 + 621 = 33534
Step 55: 33534 + 621 = 34155
Step 56: 34155 + 621 = 34776
Step 57: 34776 + 621 = 35397
Step 58: 35397 + 621 = 36018
Step 59: 36018 + 621 = 36639
Step 60: 36639 + 621 = 37260
Step 61: 37260 + 621 = 37881
Step 62: 37881 + 621 = 38502
Step 63: 38502 + 621 = 39123
Step 64: 39123 + 621 = 39744
Step 65: 39744 + 621 = 40365
Step 66: 40365 + 621 = 40986
Step 67: 40986 + 621 = 41607
Step 68: 41607 + 621 = 42228
Step 69: 42228 + 621 = 42849
Step 70: 42849 + 621 = 43470
Step 71: 43470 + 621 = 44091
Step 72: 44091 + 621 = 44712
Step 73: 44712 + 621 = 45333
Step 74: 45333 + 621 = 45954
Step 75: 45954 + 621 = 46575
Step 76: 46575 + 621 = 47196
Step 77: 47196 + 621 = 47817
Step 78: 47817 + 621 = 48438
Step 79: 48438 + 621 = 49059
Step 80: 49059 + 621 = 49680
Step 81: 49680 + 621 = 50301
Step 82: 50301 + 621 = 50922
Step 83: 50922 + 621 = 51543
Step 84: 51543 + 621 = 52164
Step 85: 52164 + 621 = 52785
Step 86: 52785 + 621 = 53406
Step 87: 53406 + 621 = 54027
Step 88: 54027 + 621 = 54648
Step 89: 54648 + 621 = 55269
Step 90: 55269 + 621 = 55890
Step 91: 55890 + 621 = 56511
Step 92: 56511 + 621 = 57132
Step 93: 57132 + 621 = 57753
Step 94: 57753 + 621 = 58374
Step 95: 58374 + 621 = 58995
Step 96: 58995 + 621 = 59616
Step 97: 59616 + 621 = 60237
Step 98: 60237 + 621 = 60858
Step 99: 60858 + 621 = 61479
Step 100: 61479 + 621 = 62100
Step 101: 62100 + 621 = 62721
Step 102: 62721 + 621 = 63342
Step 103: 63342 + 621 = 63963
Step 104: 63963 + 621 = 64584
Step 105: 64584 + 621 = 65205
Step 106: 65205 + 621 = 65826
Step 107: 65826 + 621 = 66447
Step 108: 66447 + 621 = 67068
Step 109: 67068 + 621 = 67689
Step 110: 67689 + 621 = 68310
Step 111: 68310 + 621 = 68931
Step 112: 68931 + 621 = 69552
Step 113: 69552 + 621 = 70173
Step 114: 70173 + 621 = 70794
Step 115: 70794 + 621 = 71415
Step 116: 71415 + 621 = 72036
Step 117: 72036 + 621 = 72657
Step 118: 72657 + 621 = 73278
Step 119: 73278 + 621 = 73899
Step 120: 73899 + 621 = 74520
Step 121: 74520 + 621 = 75141
Step 122: 75141 + 621 = 75762
Step 123: 75762 + 621 = 76383
Step 124: 76383 + 621 = 77004
Step 125: 77004 + 621 = 77625
Step 126: 77625 + 621 = 78246
Step 127: 78246 + 621 = 78867
Step 128: 78867 + 621 = 79488
Step 129: 79488 + 621 = 80109
Step 130: 80109 + 621 = 80730
Step 131: 80730 + 621 = 81351
Step 132: 81351 + 621 = 81972
Step 133: 81972 + 621 = 82593
Step 134: 82593 + 621 = 83214
Step 135: 83214 + 621 = 83835
Step 136: 83835 + 621 = 84456
Step 137: 84456 + 621 = 85077
Step 138: 85077 + 621 = 85698
Step 139: 85698 + 621 = 86319
Step 140: 86319 + 621 = 86940
Step 141: 86940 + 621 = 87561
Step 142: 87561 + 621 = 88182
Step 143: 88182 + 621 = 88803
Step 144: 88803 + 621 = 89424
Step 145: 89424 + 621 = 90045
Step 146: 90045 + 621 = 90666
Step 147: 90666 + 621 = 91287
Step 148: 91287 + 621 = 91908
Step 149: 91908 + 621 = 92529
Step 150: 92529 + 621 = 93150
Step 151: 93150 + 621 = 93771
Step 152: 93771 + 621 = 94392
Step 153: 94392 + 621 = 95013
Step 154: 95013 + 621 = 95634
Step 155: 95634 + 621 = 96255
Step 156: 96255 + 621 = 96876
Step 157: 96876 + 621 = 97497
Step 158: 97497 + 621 = 98118
Step 159: 98118 + 621 = 98739
Step 160: 98739 + 621 = 99360
Step 161: 99360 + 621 = 99981
Step 162: 99981 + 621 = 100602
Step 163: 100602 + 621 = 101223
Step 164: 101223 + 621 = 101844
Step 165: 101844 + 621 = 102465
Step 166: 102465 + 621 = 103086
Step 167: 103086 + 621 = 103707
Step 168: 103707 + 621 = 104328
Step 169: 104328 + 621 = 104949
Step 170: 104949 + 621 = 105570
Step 171: 105570 + 621 = 106191
Step 172: 106191 + 621 = 106812
Step 173: 106812 + 621 = 107433
Step 174: 107433 + 621 = 108054
Step 175: 108054 + 621 = 108675
Step 176: 108675 + 621 = 109296
Step 177: 109296 + 621 = 109917
Step 178: 109917 + 621 = 110538
Step 179: 110538 + 621 = 111159
Step 180: 111159 + 621 = 111780
Step 181: 111780 + 621 = 112401
Step 182: 112401 + 621 = 113022
Step 183: 113022 + 621 = 113643
Step 184: 113643 + 621 = 114264
Step 185: 114264 + 621 = 114885
Step 186: 114885 + 621 = 115506
Step 187: 115506 + 621 = 116127
Step 188: 116127 + 621 = 116748
Step 189: 116748 + 621 = 117369
Step 190: 117369 + 621 = 117990
Step 191: 117990 + 621 = 118611
Step 192: 118611 + 621 = 119232
Step 193: 119232 + 621 = 119853
Step 194: 119853 + 621 = 120474
Step 195: 120474 + 621 = 121095
Step 196: 121095 + 621 = 121716
Step 197: 121716 + 621 = 122337
Step 198: 122337 + 621 = 122958
Step 199: 122958 + 621 = 123579
Step 200: 123579 + 621 = 124200
Step 201: 124200 + 621 = 124821
Step 202: 124821 + 621 = 125442
Step 203: 125442 + 621 = 126063
Step 204: 126063 + 621 = 126684
Step 205: 126684 + 621 = 127305
Step 206: 127305 + 621 = 127926
Step 207: 127926 + 621 = 128547
Step 208: 128547 + 621 = 129168
Step 209: 129168 + 621 = 129789
Step 210: 129789 + 621 = 130410
Step 211: 130410 + 621 = 131031
Step 212: 131031 + 621 = 131652
Step 213: 131652 + 621 = 132273
Step 214: 132273 + 621 = 132894
Step 215: 132894 + 621 = 133515
Step 216: 133515 + 621 = 134136
Step 217: 134136 + 621 = 134757
Step 218: 134757 + 621 = 135378
Step 219: 135378 + 621 = 135999
Step 220: 135999 + 621 = 136620
Step 221: 136620 + 621 = 137241
Step 222: 137241 + 621 = 137862
Step 223: 137862 + 621 = 138483
Step 224: 138483 + 621 = 139104
Step 225: 139104 + 621 = 139725
Step 226: 139725 + 621 = 140346
Step 227: 140346 + 621 = 140967
Step 228: 140967 + 621 = 141588
Step 229: 141588 + 621 = 142209
Step 230: 142209 + 621 = 142830
Step 231: 142830 + 621 = 143451
Step 232: 143451 + 621 = 144072
Step 233: 144072 + 621 = 144693
Step 234: 144693 + 621 = 145314
Step 235: 145314 + 621 = 145935
Step 236: 145935 + 621 = 146556
Step 237: 146556 + 621 = 147177
Step 238: 147177 + 621 = 147798
Step 239: 147798 + 621 = 148419
Step 240: 148419 + 621 = 149040
Step 241: 149040 + 621 = 149661
Step 242: 149661 + 621 = 150282
Step 243: 150282 + 621 = 150903
Step 244: 150903 + 621 = 151524
Step 245: 151524 + 621 = 152145
Step 246: 152145 + 621 = 152766
Step 247: 152766 + 621 = 153387
Step 248: 153387 + 621 = 154008
Step 249: 154008 + 621 = 154629
Step 250: 154629 + 621 = 155250
Step 251: 155250 + 621 = 155871
Step 252: 155871 + 621 = 156492
Step 253: 156492 + 621 = 157113
Step 254: 157113 + 621 = 157734
Step 255: 157734 + 621 = 158355
Step 256: 158355 + 621 = 158976
Step 257: 158976 + 621 = 159597
Step 258: 159597 + 621 = 160218
Step 259: 160218 + 621 = 160839
Step 260: 160839 + 621 = 161460
Step 261: 161460 + 621 = 162081
Step 262: 162081 + 621 = 162702
Step 263: 162702 + 621 = 163323
Step 264: 163323 + 621 = 163944
Step 265: 163944 + 621 = 164565
Step 266: 164565 + 621 = 165186
Step 267: 165186 + 621 = 165807
Step 268: 165807 + 621 = 166428
Step 269: 166428 + 621 = 167049
Step 270: 167049 + 621 = 167670
Step 271: 167670 + 621 = 168291
Step 272: 168291 + 621 = 168912
Step 273: 168912 + 621 = 169533
Step 274: 169533 + 621 = 170154
Step 275: 170154 + 621 = 170775
Step 276: 170775 + 621 = 171396
Step 277: 171396 + 621 = 172017
Step 278: 172017 + 621 = 172638
Step 279: 172638 + 621 = 173259
Step 280: 173259 + 621 = 173880
Step 281: 173880 + 621 = 174501
Step 282: 174501 + 621 = 175122
Step 283: 175122 + 621 = 175743
Step 284: 175743 + 621 = 176364
Step 285: 176364 + 621 = 176985
Step 286: 176985 + 621 = 177606
Step 287: 177606 + 621 = 178227
Step 288: 178227 + 621 = 178848
Step 289: 178848 + 621 = 179469
Step 290: 179469 + 621 = 180090
Step 291: 180090 + 621 = 180711
Step 292: 180711 + 621 = 181332
Step 293: 181332 + 621 = 181953
Step 294: 181953 + 621 = 182574
Step 295: 182574 + 621 = 183195
Step 296: 183195 + 621 = 183816
Step 297: 183816 + 621 = 184437
Step 298: 184437 + 621 = 185058
Step 299: 185058 + 621 = 185679
Step 300: 185679 + 621 = 186300
Step 301: 186300 + 621 = 186921
Step 302: 186921 + 621 = 187542
Step 303: 187542 + 621 = 188163
Step 304: 188163 + 621 = 188784
Step 305: 188784 + 621 = 189405
Step 306: 189405 + 621 = 190026
Step 307: 190026 + 621 = 190647
Step 308: 190647 + 621 = 191268
Step 309: 191268 + 621 = 191889
Step 310: 191889 + 621 = 192510
Step 311: 192510 + 621 = 193131
Step 312: 193131 + 621 = 193752
Step 313: 193752 + 621 = 194373
Step 314: 194373 + 621 = 194994
Step 315: 194994 + 621 = 195615
Step 316: 195615 + 621 = 196236
Step 317: 196236 + 621 = 196857
Step 318: 196857 + 621 = 197478
Step 319: 197478 + 621 = 198099
Step 320: 198099 + 621 = 198720
Step 321: 198720 + 621 = 199341
Step 322: 199341 + 621 = 199962
Step 323: 199962 + 621 = 200583
Step 324: 200583 + 621 = 201204
Step 325: 201204 + 621 = 201825
Step 326: 201825 + 621 = 202446
Step 327: 202446 + 621 = 203067
Step 328: 203067 + 621 = 203688
Step 329: 203688 + 621 = 204309
Step 330: 204309 + 621 = 204930
Step 331: 204930 + 621 = 205551
Step 332: 205551 + 621 = 206172
Step 333: 206172 + 621 = 206793
Step 334: 206793 + 621 = 207414
Step 335: 207414 + 621 = 208035
Step 336: 208035 + 621 = 208656
Step 337: 208656 + 621 = 209277
Step 338: 209277 + 621 = 209898
Step 339: 209898 + 621 = 210519
Step 340: 210519 + 621 = 211140
Step 341: 211140 + 621 = 211761
Step 342: 211761 + 621 = 212382
Step 343: 212382 + 621 = 213003
Step 344: 213003 + 621 = 213624
Step 345: 213624 + 621 = 214245
Step 346: 214245 + 621 = 214866
Step 347: 214866 + 621 = 215487
Step 348: 215487 + 621 = 216108
Step 349: 216108 + 621 = 216729
Step 350: 216729 + 621 = 217350
Step 351: 217350 + 621 = 217971
Step 352: 217971 + 621 = 218592
Step 353: 218592 + 621 = 219213
Step 354: 219213 + 621 = 219834
Step 355: 219834 + 621 = 220455
Step 356: 220455 + 621 = 221076
Step 357: 221076 + 621 = 221697
Step 358: 221697 + 621 = 222318
Step 359: 222318 + 621 = 222939
Step 360: 222939 + 621 = 223560
Step 361: 223560 + 621 = 224181
Step 362: 224181 + 621 = 224802
Step 363: 224802 + 621 = 225423
Step 364: 225423 + 621 = 226044
Step 365: 226044 + 621 = 226665
Step 366: 226665 + 621 = 227286
Step 367: 227286 + 621 = 227907
Step 368: 227907 + 621 = 228528
Step 369: 228528 + 621 = 229149
Step 370: 229149 + 621 = 229770
Step 371: 229770 + 621 = 230391
Step 372: 230391 + 621 = 231012
Step 373: 231012 + 621 = 231633
Step 374: 231633 + 621 = 232254
Step 375: 232254 + 621 = 232875
Step 376: 232875 + 621 = 233496
Step 377: 233496 + 621 = 234117
Step 378: 234117 + 621 = 234738
Step 379: 234738 + 621 = 235359
Step 380: 235359 + 621 = 235980
Step 381: 235980 + 621 = 236601
Step 382: 236601 + 621 = 237222
Step 383: 237222 + 621 = 237843
Step 384: 237843 + 621 = 238464
Step 385: 238464 + 621 = 239085
Step 386: 239085 + 621 = 239706
Step 387: 239706 + 621 = 240327
Step 388: 240327 + 621 = 240948
Step 389: 240948 + 621 = 241569
Step 390: 241569 + 621 = 242190
Step 391: 242190 + 621 = 242811
Step 392: 242811 + 621 = 243432
Step 393: 243432 + 621 = 244053
Step 394: 244053 + 621 = 244674
Step 395: 244674 + 621 = 245295
Step 396: 245295 + 621 = 245916
Step 397: 245916 + 621 = 246537
Step 398: 246537 + 621 = 247158
Step 399: 247158 + 621 = 247779
Step 400: 247779 + 621 = 248400
Step 401: 248400 + 621 = 249021
Step 402: 249021 + 621 = 249642
Step 403: 249642 + 621 = 250263
Step 404: 250263 + 621 = 250884
Step 405: 250884 + 621 = 251505
Step 406: 251505 + 621 = 252126
Step 407: 252126 + 621 = 252747
Step 408: 252747 + 621 = 253368

So, 621*408 = 253368