Let's roll up our sleeves and solve this. We have 843 and we're going to multiply it by 445, essentially adding 843 to itself 445 times.
Step 1: 0 + 843 = 843
Step 2: 843 + 843 = 1686
Step 3: 1686 + 843 = 2529
Step 4: 2529 + 843 = 3372
Step 5: 3372 + 843 = 4215
Step 6: 4215 + 843 = 5058
Step 7: 5058 + 843 = 5901
Step 8: 5901 + 843 = 6744
Step 9: 6744 + 843 = 7587
Step 10: 7587 + 843 = 8430
Step 11: 8430 + 843 = 9273
Step 12: 9273 + 843 = 10116
Step 13: 10116 + 843 = 10959
Step 14: 10959 + 843 = 11802
Step 15: 11802 + 843 = 12645
Step 16: 12645 + 843 = 13488
Step 17: 13488 + 843 = 14331
Step 18: 14331 + 843 = 15174
Step 19: 15174 + 843 = 16017
Step 20: 16017 + 843 = 16860
Step 21: 16860 + 843 = 17703
Step 22: 17703 + 843 = 18546
Step 23: 18546 + 843 = 19389
Step 24: 19389 + 843 = 20232
Step 25: 20232 + 843 = 21075
Step 26: 21075 + 843 = 21918
Step 27: 21918 + 843 = 22761
Step 28: 22761 + 843 = 23604
Step 29: 23604 + 843 = 24447
Step 30: 24447 + 843 = 25290
Step 31: 25290 + 843 = 26133
Step 32: 26133 + 843 = 26976
Step 33: 26976 + 843 = 27819
Step 34: 27819 + 843 = 28662
Step 35: 28662 + 843 = 29505
Step 36: 29505 + 843 = 30348
Step 37: 30348 + 843 = 31191
Step 38: 31191 + 843 = 32034
Step 39: 32034 + 843 = 32877
Step 40: 32877 + 843 = 33720
Step 41: 33720 + 843 = 34563
Step 42: 34563 + 843 = 35406
Step 43: 35406 + 843 = 36249
Step 44: 36249 + 843 = 37092
Step 45: 37092 + 843 = 37935
Step 46: 37935 + 843 = 38778
Step 47: 38778 + 843 = 39621
Step 48: 39621 + 843 = 40464
Step 49: 40464 + 843 = 41307
Step 50: 41307 + 843 = 42150
Step 51: 42150 + 843 = 42993
Step 52: 42993 + 843 = 43836
Step 53: 43836 + 843 = 44679
Step 54: 44679 + 843 = 45522
Step 55: 45522 + 843 = 46365
Step 56: 46365 + 843 = 47208
Step 57: 47208 + 843 = 48051
Step 58: 48051 + 843 = 48894
Step 59: 48894 + 843 = 49737
Step 60: 49737 + 843 = 50580
Step 61: 50580 + 843 = 51423
Step 62: 51423 + 843 = 52266
Step 63: 52266 + 843 = 53109
Step 64: 53109 + 843 = 53952
Step 65: 53952 + 843 = 54795
Step 66: 54795 + 843 = 55638
Step 67: 55638 + 843 = 56481
Step 68: 56481 + 843 = 57324
Step 69: 57324 + 843 = 58167
Step 70: 58167 + 843 = 59010
Step 71: 59010 + 843 = 59853
Step 72: 59853 + 843 = 60696
Step 73: 60696 + 843 = 61539
Step 74: 61539 + 843 = 62382
Step 75: 62382 + 843 = 63225
Step 76: 63225 + 843 = 64068
Step 77: 64068 + 843 = 64911
Step 78: 64911 + 843 = 65754
Step 79: 65754 + 843 = 66597
Step 80: 66597 + 843 = 67440
Step 81: 67440 + 843 = 68283
Step 82: 68283 + 843 = 69126
Step 83: 69126 + 843 = 69969
Step 84: 69969 + 843 = 70812
Step 85: 70812 + 843 = 71655
Step 86: 71655 + 843 = 72498
Step 87: 72498 + 843 = 73341
Step 88: 73341 + 843 = 74184
Step 89: 74184 + 843 = 75027
Step 90: 75027 + 843 = 75870
Step 91: 75870 + 843 = 76713
Step 92: 76713 + 843 = 77556
Step 93: 77556 + 843 = 78399
Step 94: 78399 + 843 = 79242
Step 95: 79242 + 843 = 80085
Step 96: 80085 + 843 = 80928
Step 97: 80928 + 843 = 81771
Step 98: 81771 + 843 = 82614
Step 99: 82614 + 843 = 83457
Step 100: 83457 + 843 = 84300
Step 101: 84300 + 843 = 85143
Step 102: 85143 + 843 = 85986
Step 103: 85986 + 843 = 86829
Step 104: 86829 + 843 = 87672
Step 105: 87672 + 843 = 88515
Step 106: 88515 + 843 = 89358
Step 107: 89358 + 843 = 90201
Step 108: 90201 + 843 = 91044
Step 109: 91044 + 843 = 91887
Step 110: 91887 + 843 = 92730
Step 111: 92730 + 843 = 93573
Step 112: 93573 + 843 = 94416
Step 113: 94416 + 843 = 95259
Step 114: 95259 + 843 = 96102
Step 115: 96102 + 843 = 96945
Step 116: 96945 + 843 = 97788
Step 117: 97788 + 843 = 98631
Step 118: 98631 + 843 = 99474
Step 119: 99474 + 843 = 100317
Step 120: 100317 + 843 = 101160
Step 121: 101160 + 843 = 102003
Step 122: 102003 + 843 = 102846
Step 123: 102846 + 843 = 103689
Step 124: 103689 + 843 = 104532
Step 125: 104532 + 843 = 105375
Step 126: 105375 + 843 = 106218
Step 127: 106218 + 843 = 107061
Step 128: 107061 + 843 = 107904
Step 129: 107904 + 843 = 108747
Step 130: 108747 + 843 = 109590
Step 131: 109590 + 843 = 110433
Step 132: 110433 + 843 = 111276
Step 133: 111276 + 843 = 112119
Step 134: 112119 + 843 = 112962
Step 135: 112962 + 843 = 113805
Step 136: 113805 + 843 = 114648
Step 137: 114648 + 843 = 115491
Step 138: 115491 + 843 = 116334
Step 139: 116334 + 843 = 117177
Step 140: 117177 + 843 = 118020
Step 141: 118020 + 843 = 118863
Step 142: 118863 + 843 = 119706
Step 143: 119706 + 843 = 120549
Step 144: 120549 + 843 = 121392
Step 145: 121392 + 843 = 122235
Step 146: 122235 + 843 = 123078
Step 147: 123078 + 843 = 123921
Step 148: 123921 + 843 = 124764
Step 149: 124764 + 843 = 125607
Step 150: 125607 + 843 = 126450
Step 151: 126450 + 843 = 127293
Step 152: 127293 + 843 = 128136
Step 153: 128136 + 843 = 128979
Step 154: 128979 + 843 = 129822
Step 155: 129822 + 843 = 130665
Step 156: 130665 + 843 = 131508
Step 157: 131508 + 843 = 132351
Step 158: 132351 + 843 = 133194
Step 159: 133194 + 843 = 134037
Step 160: 134037 + 843 = 134880
Step 161: 134880 + 843 = 135723
Step 162: 135723 + 843 = 136566
Step 163: 136566 + 843 = 137409
Step 164: 137409 + 843 = 138252
Step 165: 138252 + 843 = 139095
Step 166: 139095 + 843 = 139938
Step 167: 139938 + 843 = 140781
Step 168: 140781 + 843 = 141624
Step 169: 141624 + 843 = 142467
Step 170: 142467 + 843 = 143310
Step 171: 143310 + 843 = 144153
Step 172: 144153 + 843 = 144996
Step 173: 144996 + 843 = 145839
Step 174: 145839 + 843 = 146682
Step 175: 146682 + 843 = 147525
Step 176: 147525 + 843 = 148368
Step 177: 148368 + 843 = 149211
Step 178: 149211 + 843 = 150054
Step 179: 150054 + 843 = 150897
Step 180: 150897 + 843 = 151740
Step 181: 151740 + 843 = 152583
Step 182: 152583 + 843 = 153426
Step 183: 153426 + 843 = 154269
Step 184: 154269 + 843 = 155112
Step 185: 155112 + 843 = 155955
Step 186: 155955 + 843 = 156798
Step 187: 156798 + 843 = 157641
Step 188: 157641 + 843 = 158484
Step 189: 158484 + 843 = 159327
Step 190: 159327 + 843 = 160170
Step 191: 160170 + 843 = 161013
Step 192: 161013 + 843 = 161856
Step 193: 161856 + 843 = 162699
Step 194: 162699 + 843 = 163542
Step 195: 163542 + 843 = 164385
Step 196: 164385 + 843 = 165228
Step 197: 165228 + 843 = 166071
Step 198: 166071 + 843 = 166914
Step 199: 166914 + 843 = 167757
Step 200: 167757 + 843 = 168600
Step 201: 168600 + 843 = 169443
Step 202: 169443 + 843 = 170286
Step 203: 170286 + 843 = 171129
Step 204: 171129 + 843 = 171972
Step 205: 171972 + 843 = 172815
Step 206: 172815 + 843 = 173658
Step 207: 173658 + 843 = 174501
Step 208: 174501 + 843 = 175344
Step 209: 175344 + 843 = 176187
Step 210: 176187 + 843 = 177030
Step 211: 177030 + 843 = 177873
Step 212: 177873 + 843 = 178716
Step 213: 178716 + 843 = 179559
Step 214: 179559 + 843 = 180402
Step 215: 180402 + 843 = 181245
Step 216: 181245 + 843 = 182088
Step 217: 182088 + 843 = 182931
Step 218: 182931 + 843 = 183774
Step 219: 183774 + 843 = 184617
Step 220: 184617 + 843 = 185460
Step 221: 185460 + 843 = 186303
Step 222: 186303 + 843 = 187146
Step 223: 187146 + 843 = 187989
Step 224: 187989 + 843 = 188832
Step 225: 188832 + 843 = 189675
Step 226: 189675 + 843 = 190518
Step 227: 190518 + 843 = 191361
Step 228: 191361 + 843 = 192204
Step 229: 192204 + 843 = 193047
Step 230: 193047 + 843 = 193890
Step 231: 193890 + 843 = 194733
Step 232: 194733 + 843 = 195576
Step 233: 195576 + 843 = 196419
Step 234: 196419 + 843 = 197262
Step 235: 197262 + 843 = 198105
Step 236: 198105 + 843 = 198948
Step 237: 198948 + 843 = 199791
Step 238: 199791 + 843 = 200634
Step 239: 200634 + 843 = 201477
Step 240: 201477 + 843 = 202320
Step 241: 202320 + 843 = 203163
Step 242: 203163 + 843 = 204006
Step 243: 204006 + 843 = 204849
Step 244: 204849 + 843 = 205692
Step 245: 205692 + 843 = 206535
Step 246: 206535 + 843 = 207378
Step 247: 207378 + 843 = 208221
Step 248: 208221 + 843 = 209064
Step 249: 209064 + 843 = 209907
Step 250: 209907 + 843 = 210750
Step 251: 210750 + 843 = 211593
Step 252: 211593 + 843 = 212436
Step 253: 212436 + 843 = 213279
Step 254: 213279 + 843 = 214122
Step 255: 214122 + 843 = 214965
Step 256: 214965 + 843 = 215808
Step 257: 215808 + 843 = 216651
Step 258: 216651 + 843 = 217494
Step 259: 217494 + 843 = 218337
Step 260: 218337 + 843 = 219180
Step 261: 219180 + 843 = 220023
Step 262: 220023 + 843 = 220866
Step 263: 220866 + 843 = 221709
Step 264: 221709 + 843 = 222552
Step 265: 222552 + 843 = 223395
Step 266: 223395 + 843 = 224238
Step 267: 224238 + 843 = 225081
Step 268: 225081 + 843 = 225924
Step 269: 225924 + 843 = 226767
Step 270: 226767 + 843 = 227610
Step 271: 227610 + 843 = 228453
Step 272: 228453 + 843 = 229296
Step 273: 229296 + 843 = 230139
Step 274: 230139 + 843 = 230982
Step 275: 230982 + 843 = 231825
Step 276: 231825 + 843 = 232668
Step 277: 232668 + 843 = 233511
Step 278: 233511 + 843 = 234354
Step 279: 234354 + 843 = 235197
Step 280: 235197 + 843 = 236040
Step 281: 236040 + 843 = 236883
Step 282: 236883 + 843 = 237726
Step 283: 237726 + 843 = 238569
Step 284: 238569 + 843 = 239412
Step 285: 239412 + 843 = 240255
Step 286: 240255 + 843 = 241098
Step 287: 241098 + 843 = 241941
Step 288: 241941 + 843 = 242784
Step 289: 242784 + 843 = 243627
Step 290: 243627 + 843 = 244470
Step 291: 244470 + 843 = 245313
Step 292: 245313 + 843 = 246156
Step 293: 246156 + 843 = 246999
Step 294: 246999 + 843 = 247842
Step 295: 247842 + 843 = 248685
Step 296: 248685 + 843 = 249528
Step 297: 249528 + 843 = 250371
Step 298: 250371 + 843 = 251214
Step 299: 251214 + 843 = 252057
Step 300: 252057 + 843 = 252900
Step 301: 252900 + 843 = 253743
Step 302: 253743 + 843 = 254586
Step 303: 254586 + 843 = 255429
Step 304: 255429 + 843 = 256272
Step 305: 256272 + 843 = 257115
Step 306: 257115 + 843 = 257958
Step 307: 257958 + 843 = 258801
Step 308: 258801 + 843 = 259644
Step 309: 259644 + 843 = 260487
Step 310: 260487 + 843 = 261330
Step 311: 261330 + 843 = 262173
Step 312: 262173 + 843 = 263016
Step 313: 263016 + 843 = 263859
Step 314: 263859 + 843 = 264702
Step 315: 264702 + 843 = 265545
Step 316: 265545 + 843 = 266388
Step 317: 266388 + 843 = 267231
Step 318: 267231 + 843 = 268074
Step 319: 268074 + 843 = 268917
Step 320: 268917 + 843 = 269760
Step 321: 269760 + 843 = 270603
Step 322: 270603 + 843 = 271446
Step 323: 271446 + 843 = 272289
Step 324: 272289 + 843 = 273132
Step 325: 273132 + 843 = 273975
Step 326: 273975 + 843 = 274818
Step 327: 274818 + 843 = 275661
Step 328: 275661 + 843 = 276504
Step 329: 276504 + 843 = 277347
Step 330: 277347 + 843 = 278190
Step 331: 278190 + 843 = 279033
Step 332: 279033 + 843 = 279876
Step 333: 279876 + 843 = 280719
Step 334: 280719 + 843 = 281562
Step 335: 281562 + 843 = 282405
Step 336: 282405 + 843 = 283248
Step 337: 283248 + 843 = 284091
Step 338: 284091 + 843 = 284934
Step 339: 284934 + 843 = 285777
Step 340: 285777 + 843 = 286620
Step 341: 286620 + 843 = 287463
Step 342: 287463 + 843 = 288306
Step 343: 288306 + 843 = 289149
Step 344: 289149 + 843 = 289992
Step 345: 289992 + 843 = 290835
Step 346: 290835 + 843 = 291678
Step 347: 291678 + 843 = 292521
Step 348: 292521 + 843 = 293364
Step 349: 293364 + 843 = 294207
Step 350: 294207 + 843 = 295050
Step 351: 295050 + 843 = 295893
Step 352: 295893 + 843 = 296736
Step 353: 296736 + 843 = 297579
Step 354: 297579 + 843 = 298422
Step 355: 298422 + 843 = 299265
Step 356: 299265 + 843 = 300108
Step 357: 300108 + 843 = 300951
Step 358: 300951 + 843 = 301794
Step 359: 301794 + 843 = 302637
Step 360: 302637 + 843 = 303480
Step 361: 303480 + 843 = 304323
Step 362: 304323 + 843 = 305166
Step 363: 305166 + 843 = 306009
Step 364: 306009 + 843 = 306852
Step 365: 306852 + 843 = 307695
Step 366: 307695 + 843 = 308538
Step 367: 308538 + 843 = 309381
Step 368: 309381 + 843 = 310224
Step 369: 310224 + 843 = 311067
Step 370: 311067 + 843 = 311910
Step 371: 311910 + 843 = 312753
Step 372: 312753 + 843 = 313596
Step 373: 313596 + 843 = 314439
Step 374: 314439 + 843 = 315282
Step 375: 315282 + 843 = 316125
Step 376: 316125 + 843 = 316968
Step 377: 316968 + 843 = 317811
Step 378: 317811 + 843 = 318654
Step 379: 318654 + 843 = 319497
Step 380: 319497 + 843 = 320340
Step 381: 320340 + 843 = 321183
Step 382: 321183 + 843 = 322026
Step 383: 322026 + 843 = 322869
Step 384: 322869 + 843 = 323712
Step 385: 323712 + 843 = 324555
Step 386: 324555 + 843 = 325398
Step 387: 325398 + 843 = 326241
Step 388: 326241 + 843 = 327084
Step 389: 327084 + 843 = 327927
Step 390: 327927 + 843 = 328770
Step 391: 328770 + 843 = 329613
Step 392: 329613 + 843 = 330456
Step 393: 330456 + 843 = 331299
Step 394: 331299 + 843 = 332142
Step 395: 332142 + 843 = 332985
Step 396: 332985 + 843 = 333828
Step 397: 333828 + 843 = 334671
Step 398: 334671 + 843 = 335514
Step 399: 335514 + 843 = 336357
Step 400: 336357 + 843 = 337200
Step 401: 337200 + 843 = 338043
Step 402: 338043 + 843 = 338886
Step 403: 338886 + 843 = 339729
Step 404: 339729 + 843 = 340572
Step 405: 340572 + 843 = 341415
Step 406: 341415 + 843 = 342258
Step 407: 342258 + 843 = 343101
Step 408: 343101 + 843 = 343944
Step 409: 343944 + 843 = 344787
Step 410: 344787 + 843 = 345630
Step 411: 345630 + 843 = 346473
Step 412: 346473 + 843 = 347316
Step 413: 347316 + 843 = 348159
Step 414: 348159 + 843 = 349002
Step 415: 349002 + 843 = 349845
Step 416: 349845 + 843 = 350688
Step 417: 350688 + 843 = 351531
Step 418: 351531 + 843 = 352374
Step 419: 352374 + 843 = 353217
Step 420: 353217 + 843 = 354060
Step 421: 354060 + 843 = 354903
Step 422: 354903 + 843 = 355746
Step 423: 355746 + 843 = 356589
Step 424: 356589 + 843 = 357432
Step 425: 357432 + 843 = 358275
Step 426: 358275 + 843 = 359118
Step 427: 359118 + 843 = 359961
Step 428: 359961 + 843 = 360804
Step 429: 360804 + 843 = 361647
Step 430: 361647 + 843 = 362490
Step 431: 362490 + 843 = 363333
Step 432: 363333 + 843 = 364176
Step 433: 364176 + 843 = 365019
Step 434: 365019 + 843 = 365862
Step 435: 365862 + 843 = 366705
Step 436: 366705 + 843 = 367548
Step 437: 367548 + 843 = 368391
Step 438: 368391 + 843 = 369234
Step 439: 369234 + 843 = 370077
Step 440: 370077 + 843 = 370920
Step 441: 370920 + 843 = 371763
Step 442: 371763 + 843 = 372606
Step 443: 372606 + 843 = 373449
Step 444: 373449 + 843 = 374292
Step 445: 374292 + 843 = 375135

So, 843*445 = 375135