Without delay, let's solve this. We've got 821 and we will be multiplying it by 410, that is, adding 821 to itself 410 times.
Step 1: 0 + 821 = 821
Step 2: 821 + 821 = 1642
Step 3: 1642 + 821 = 2463
Step 4: 2463 + 821 = 3284
Step 5: 3284 + 821 = 4105
Step 6: 4105 + 821 = 4926
Step 7: 4926 + 821 = 5747
Step 8: 5747 + 821 = 6568
Step 9: 6568 + 821 = 7389
Step 10: 7389 + 821 = 8210
Step 11: 8210 + 821 = 9031
Step 12: 9031 + 821 = 9852
Step 13: 9852 + 821 = 10673
Step 14: 10673 + 821 = 11494
Step 15: 11494 + 821 = 12315
Step 16: 12315 + 821 = 13136
Step 17: 13136 + 821 = 13957
Step 18: 13957 + 821 = 14778
Step 19: 14778 + 821 = 15599
Step 20: 15599 + 821 = 16420
Step 21: 16420 + 821 = 17241
Step 22: 17241 + 821 = 18062
Step 23: 18062 + 821 = 18883
Step 24: 18883 + 821 = 19704
Step 25: 19704 + 821 = 20525
Step 26: 20525 + 821 = 21346
Step 27: 21346 + 821 = 22167
Step 28: 22167 + 821 = 22988
Step 29: 22988 + 821 = 23809
Step 30: 23809 + 821 = 24630
Step 31: 24630 + 821 = 25451
Step 32: 25451 + 821 = 26272
Step 33: 26272 + 821 = 27093
Step 34: 27093 + 821 = 27914
Step 35: 27914 + 821 = 28735
Step 36: 28735 + 821 = 29556
Step 37: 29556 + 821 = 30377
Step 38: 30377 + 821 = 31198
Step 39: 31198 + 821 = 32019
Step 40: 32019 + 821 = 32840
Step 41: 32840 + 821 = 33661
Step 42: 33661 + 821 = 34482
Step 43: 34482 + 821 = 35303
Step 44: 35303 + 821 = 36124
Step 45: 36124 + 821 = 36945
Step 46: 36945 + 821 = 37766
Step 47: 37766 + 821 = 38587
Step 48: 38587 + 821 = 39408
Step 49: 39408 + 821 = 40229
Step 50: 40229 + 821 = 41050
Step 51: 41050 + 821 = 41871
Step 52: 41871 + 821 = 42692
Step 53: 42692 + 821 = 43513
Step 54: 43513 + 821 = 44334
Step 55: 44334 + 821 = 45155
Step 56: 45155 + 821 = 45976
Step 57: 45976 + 821 = 46797
Step 58: 46797 + 821 = 47618
Step 59: 47618 + 821 = 48439
Step 60: 48439 + 821 = 49260
Step 61: 49260 + 821 = 50081
Step 62: 50081 + 821 = 50902
Step 63: 50902 + 821 = 51723
Step 64: 51723 + 821 = 52544
Step 65: 52544 + 821 = 53365
Step 66: 53365 + 821 = 54186
Step 67: 54186 + 821 = 55007
Step 68: 55007 + 821 = 55828
Step 69: 55828 + 821 = 56649
Step 70: 56649 + 821 = 57470
Step 71: 57470 + 821 = 58291
Step 72: 58291 + 821 = 59112
Step 73: 59112 + 821 = 59933
Step 74: 59933 + 821 = 60754
Step 75: 60754 + 821 = 61575
Step 76: 61575 + 821 = 62396
Step 77: 62396 + 821 = 63217
Step 78: 63217 + 821 = 64038
Step 79: 64038 + 821 = 64859
Step 80: 64859 + 821 = 65680
Step 81: 65680 + 821 = 66501
Step 82: 66501 + 821 = 67322
Step 83: 67322 + 821 = 68143
Step 84: 68143 + 821 = 68964
Step 85: 68964 + 821 = 69785
Step 86: 69785 + 821 = 70606
Step 87: 70606 + 821 = 71427
Step 88: 71427 + 821 = 72248
Step 89: 72248 + 821 = 73069
Step 90: 73069 + 821 = 73890
Step 91: 73890 + 821 = 74711
Step 92: 74711 + 821 = 75532
Step 93: 75532 + 821 = 76353
Step 94: 76353 + 821 = 77174
Step 95: 77174 + 821 = 77995
Step 96: 77995 + 821 = 78816
Step 97: 78816 + 821 = 79637
Step 98: 79637 + 821 = 80458
Step 99: 80458 + 821 = 81279
Step 100: 81279 + 821 = 82100
Step 101: 82100 + 821 = 82921
Step 102: 82921 + 821 = 83742
Step 103: 83742 + 821 = 84563
Step 104: 84563 + 821 = 85384
Step 105: 85384 + 821 = 86205
Step 106: 86205 + 821 = 87026
Step 107: 87026 + 821 = 87847
Step 108: 87847 + 821 = 88668
Step 109: 88668 + 821 = 89489
Step 110: 89489 + 821 = 90310
Step 111: 90310 + 821 = 91131
Step 112: 91131 + 821 = 91952
Step 113: 91952 + 821 = 92773
Step 114: 92773 + 821 = 93594
Step 115: 93594 + 821 = 94415
Step 116: 94415 + 821 = 95236
Step 117: 95236 + 821 = 96057
Step 118: 96057 + 821 = 96878
Step 119: 96878 + 821 = 97699
Step 120: 97699 + 821 = 98520
Step 121: 98520 + 821 = 99341
Step 122: 99341 + 821 = 100162
Step 123: 100162 + 821 = 100983
Step 124: 100983 + 821 = 101804
Step 125: 101804 + 821 = 102625
Step 126: 102625 + 821 = 103446
Step 127: 103446 + 821 = 104267
Step 128: 104267 + 821 = 105088
Step 129: 105088 + 821 = 105909
Step 130: 105909 + 821 = 106730
Step 131: 106730 + 821 = 107551
Step 132: 107551 + 821 = 108372
Step 133: 108372 + 821 = 109193
Step 134: 109193 + 821 = 110014
Step 135: 110014 + 821 = 110835
Step 136: 110835 + 821 = 111656
Step 137: 111656 + 821 = 112477
Step 138: 112477 + 821 = 113298
Step 139: 113298 + 821 = 114119
Step 140: 114119 + 821 = 114940
Step 141: 114940 + 821 = 115761
Step 142: 115761 + 821 = 116582
Step 143: 116582 + 821 = 117403
Step 144: 117403 + 821 = 118224
Step 145: 118224 + 821 = 119045
Step 146: 119045 + 821 = 119866
Step 147: 119866 + 821 = 120687
Step 148: 120687 + 821 = 121508
Step 149: 121508 + 821 = 122329
Step 150: 122329 + 821 = 123150
Step 151: 123150 + 821 = 123971
Step 152: 123971 + 821 = 124792
Step 153: 124792 + 821 = 125613
Step 154: 125613 + 821 = 126434
Step 155: 126434 + 821 = 127255
Step 156: 127255 + 821 = 128076
Step 157: 128076 + 821 = 128897
Step 158: 128897 + 821 = 129718
Step 159: 129718 + 821 = 130539
Step 160: 130539 + 821 = 131360
Step 161: 131360 + 821 = 132181
Step 162: 132181 + 821 = 133002
Step 163: 133002 + 821 = 133823
Step 164: 133823 + 821 = 134644
Step 165: 134644 + 821 = 135465
Step 166: 135465 + 821 = 136286
Step 167: 136286 + 821 = 137107
Step 168: 137107 + 821 = 137928
Step 169: 137928 + 821 = 138749
Step 170: 138749 + 821 = 139570
Step 171: 139570 + 821 = 140391
Step 172: 140391 + 821 = 141212
Step 173: 141212 + 821 = 142033
Step 174: 142033 + 821 = 142854
Step 175: 142854 + 821 = 143675
Step 176: 143675 + 821 = 144496
Step 177: 144496 + 821 = 145317
Step 178: 145317 + 821 = 146138
Step 179: 146138 + 821 = 146959
Step 180: 146959 + 821 = 147780
Step 181: 147780 + 821 = 148601
Step 182: 148601 + 821 = 149422
Step 183: 149422 + 821 = 150243
Step 184: 150243 + 821 = 151064
Step 185: 151064 + 821 = 151885
Step 186: 151885 + 821 = 152706
Step 187: 152706 + 821 = 153527
Step 188: 153527 + 821 = 154348
Step 189: 154348 + 821 = 155169
Step 190: 155169 + 821 = 155990
Step 191: 155990 + 821 = 156811
Step 192: 156811 + 821 = 157632
Step 193: 157632 + 821 = 158453
Step 194: 158453 + 821 = 159274
Step 195: 159274 + 821 = 160095
Step 196: 160095 + 821 = 160916
Step 197: 160916 + 821 = 161737
Step 198: 161737 + 821 = 162558
Step 199: 162558 + 821 = 163379
Step 200: 163379 + 821 = 164200
Step 201: 164200 + 821 = 165021
Step 202: 165021 + 821 = 165842
Step 203: 165842 + 821 = 166663
Step 204: 166663 + 821 = 167484
Step 205: 167484 + 821 = 168305
Step 206: 168305 + 821 = 169126
Step 207: 169126 + 821 = 169947
Step 208: 169947 + 821 = 170768
Step 209: 170768 + 821 = 171589
Step 210: 171589 + 821 = 172410
Step 211: 172410 + 821 = 173231
Step 212: 173231 + 821 = 174052
Step 213: 174052 + 821 = 174873
Step 214: 174873 + 821 = 175694
Step 215: 175694 + 821 = 176515
Step 216: 176515 + 821 = 177336
Step 217: 177336 + 821 = 178157
Step 218: 178157 + 821 = 178978
Step 219: 178978 + 821 = 179799
Step 220: 179799 + 821 = 180620
Step 221: 180620 + 821 = 181441
Step 222: 181441 + 821 = 182262
Step 223: 182262 + 821 = 183083
Step 224: 183083 + 821 = 183904
Step 225: 183904 + 821 = 184725
Step 226: 184725 + 821 = 185546
Step 227: 185546 + 821 = 186367
Step 228: 186367 + 821 = 187188
Step 229: 187188 + 821 = 188009
Step 230: 188009 + 821 = 188830
Step 231: 188830 + 821 = 189651
Step 232: 189651 + 821 = 190472
Step 233: 190472 + 821 = 191293
Step 234: 191293 + 821 = 192114
Step 235: 192114 + 821 = 192935
Step 236: 192935 + 821 = 193756
Step 237: 193756 + 821 = 194577
Step 238: 194577 + 821 = 195398
Step 239: 195398 + 821 = 196219
Step 240: 196219 + 821 = 197040
Step 241: 197040 + 821 = 197861
Step 242: 197861 + 821 = 198682
Step 243: 198682 + 821 = 199503
Step 244: 199503 + 821 = 200324
Step 245: 200324 + 821 = 201145
Step 246: 201145 + 821 = 201966
Step 247: 201966 + 821 = 202787
Step 248: 202787 + 821 = 203608
Step 249: 203608 + 821 = 204429
Step 250: 204429 + 821 = 205250
Step 251: 205250 + 821 = 206071
Step 252: 206071 + 821 = 206892
Step 253: 206892 + 821 = 207713
Step 254: 207713 + 821 = 208534
Step 255: 208534 + 821 = 209355
Step 256: 209355 + 821 = 210176
Step 257: 210176 + 821 = 210997
Step 258: 210997 + 821 = 211818
Step 259: 211818 + 821 = 212639
Step 260: 212639 + 821 = 213460
Step 261: 213460 + 821 = 214281
Step 262: 214281 + 821 = 215102
Step 263: 215102 + 821 = 215923
Step 264: 215923 + 821 = 216744
Step 265: 216744 + 821 = 217565
Step 266: 217565 + 821 = 218386
Step 267: 218386 + 821 = 219207
Step 268: 219207 + 821 = 220028
Step 269: 220028 + 821 = 220849
Step 270: 220849 + 821 = 221670
Step 271: 221670 + 821 = 222491
Step 272: 222491 + 821 = 223312
Step 273: 223312 + 821 = 224133
Step 274: 224133 + 821 = 224954
Step 275: 224954 + 821 = 225775
Step 276: 225775 + 821 = 226596
Step 277: 226596 + 821 = 227417
Step 278: 227417 + 821 = 228238
Step 279: 228238 + 821 = 229059
Step 280: 229059 + 821 = 229880
Step 281: 229880 + 821 = 230701
Step 282: 230701 + 821 = 231522
Step 283: 231522 + 821 = 232343
Step 284: 232343 + 821 = 233164
Step 285: 233164 + 821 = 233985
Step 286: 233985 + 821 = 234806
Step 287: 234806 + 821 = 235627
Step 288: 235627 + 821 = 236448
Step 289: 236448 + 821 = 237269
Step 290: 237269 + 821 = 238090
Step 291: 238090 + 821 = 238911
Step 292: 238911 + 821 = 239732
Step 293: 239732 + 821 = 240553
Step 294: 240553 + 821 = 241374
Step 295: 241374 + 821 = 242195
Step 296: 242195 + 821 = 243016
Step 297: 243016 + 821 = 243837
Step 298: 243837 + 821 = 244658
Step 299: 244658 + 821 = 245479
Step 300: 245479 + 821 = 246300
Step 301: 246300 + 821 = 247121
Step 302: 247121 + 821 = 247942
Step 303: 247942 + 821 = 248763
Step 304: 248763 + 821 = 249584
Step 305: 249584 + 821 = 250405
Step 306: 250405 + 821 = 251226
Step 307: 251226 + 821 = 252047
Step 308: 252047 + 821 = 252868
Step 309: 252868 + 821 = 253689
Step 310: 253689 + 821 = 254510
Step 311: 254510 + 821 = 255331
Step 312: 255331 + 821 = 256152
Step 313: 256152 + 821 = 256973
Step 314: 256973 + 821 = 257794
Step 315: 257794 + 821 = 258615
Step 316: 258615 + 821 = 259436
Step 317: 259436 + 821 = 260257
Step 318: 260257 + 821 = 261078
Step 319: 261078 + 821 = 261899
Step 320: 261899 + 821 = 262720
Step 321: 262720 + 821 = 263541
Step 322: 263541 + 821 = 264362
Step 323: 264362 + 821 = 265183
Step 324: 265183 + 821 = 266004
Step 325: 266004 + 821 = 266825
Step 326: 266825 + 821 = 267646
Step 327: 267646 + 821 = 268467
Step 328: 268467 + 821 = 269288
Step 329: 269288 + 821 = 270109
Step 330: 270109 + 821 = 270930
Step 331: 270930 + 821 = 271751
Step 332: 271751 + 821 = 272572
Step 333: 272572 + 821 = 273393
Step 334: 273393 + 821 = 274214
Step 335: 274214 + 821 = 275035
Step 336: 275035 + 821 = 275856
Step 337: 275856 + 821 = 276677
Step 338: 276677 + 821 = 277498
Step 339: 277498 + 821 = 278319
Step 340: 278319 + 821 = 279140
Step 341: 279140 + 821 = 279961
Step 342: 279961 + 821 = 280782
Step 343: 280782 + 821 = 281603
Step 344: 281603 + 821 = 282424
Step 345: 282424 + 821 = 283245
Step 346: 283245 + 821 = 284066
Step 347: 284066 + 821 = 284887
Step 348: 284887 + 821 = 285708
Step 349: 285708 + 821 = 286529
Step 350: 286529 + 821 = 287350
Step 351: 287350 + 821 = 288171
Step 352: 288171 + 821 = 288992
Step 353: 288992 + 821 = 289813
Step 354: 289813 + 821 = 290634
Step 355: 290634 + 821 = 291455
Step 356: 291455 + 821 = 292276
Step 357: 292276 + 821 = 293097
Step 358: 293097 + 821 = 293918
Step 359: 293918 + 821 = 294739
Step 360: 294739 + 821 = 295560
Step 361: 295560 + 821 = 296381
Step 362: 296381 + 821 = 297202
Step 363: 297202 + 821 = 298023
Step 364: 298023 + 821 = 298844
Step 365: 298844 + 821 = 299665
Step 366: 299665 + 821 = 300486
Step 367: 300486 + 821 = 301307
Step 368: 301307 + 821 = 302128
Step 369: 302128 + 821 = 302949
Step 370: 302949 + 821 = 303770
Step 371: 303770 + 821 = 304591
Step 372: 304591 + 821 = 305412
Step 373: 305412 + 821 = 306233
Step 374: 306233 + 821 = 307054
Step 375: 307054 + 821 = 307875
Step 376: 307875 + 821 = 308696
Step 377: 308696 + 821 = 309517
Step 378: 309517 + 821 = 310338
Step 379: 310338 + 821 = 311159
Step 380: 311159 + 821 = 311980
Step 381: 311980 + 821 = 312801
Step 382: 312801 + 821 = 313622
Step 383: 313622 + 821 = 314443
Step 384: 314443 + 821 = 315264
Step 385: 315264 + 821 = 316085
Step 386: 316085 + 821 = 316906
Step 387: 316906 + 821 = 317727
Step 388: 317727 + 821 = 318548
Step 389: 318548 + 821 = 319369
Step 390: 319369 + 821 = 320190
Step 391: 320190 + 821 = 321011
Step 392: 321011 + 821 = 321832
Step 393: 321832 + 821 = 322653
Step 394: 322653 + 821 = 323474
Step 395: 323474 + 821 = 324295
Step 396: 324295 + 821 = 325116
Step 397: 325116 + 821 = 325937
Step 398: 325937 + 821 = 326758
Step 399: 326758 + 821 = 327579
Step 400: 327579 + 821 = 328400
Step 401: 328400 + 821 = 329221
Step 402: 329221 + 821 = 330042
Step 403: 330042 + 821 = 330863
Step 404: 330863 + 821 = 331684
Step 405: 331684 + 821 = 332505
Step 406: 332505 + 821 = 333326
Step 407: 333326 + 821 = 334147
Step 408: 334147 + 821 = 334968
Step 409: 334968 + 821 = 335789
Step 410: 335789 + 821 = 336610

So, 821*410 = 336610