Let's get this math done. We have 81 and we're going to multiply it by 358. This is the same as taking 81 and adding it to itself 358 times.
Step 1: 0 + 81 = 81
Step 2: 81 + 81 = 162
Step 3: 162 + 81 = 243
Step 4: 243 + 81 = 324
Step 5: 324 + 81 = 405
Step 6: 405 + 81 = 486
Step 7: 486 + 81 = 567
Step 8: 567 + 81 = 648
Step 9: 648 + 81 = 729
Step 10: 729 + 81 = 810
Step 11: 810 + 81 = 891
Step 12: 891 + 81 = 972
Step 13: 972 + 81 = 1053
Step 14: 1053 + 81 = 1134
Step 15: 1134 + 81 = 1215
Step 16: 1215 + 81 = 1296
Step 17: 1296 + 81 = 1377
Step 18: 1377 + 81 = 1458
Step 19: 1458 + 81 = 1539
Step 20: 1539 + 81 = 1620
Step 21: 1620 + 81 = 1701
Step 22: 1701 + 81 = 1782
Step 23: 1782 + 81 = 1863
Step 24: 1863 + 81 = 1944
Step 25: 1944 + 81 = 2025
Step 26: 2025 + 81 = 2106
Step 27: 2106 + 81 = 2187
Step 28: 2187 + 81 = 2268
Step 29: 2268 + 81 = 2349
Step 30: 2349 + 81 = 2430
Step 31: 2430 + 81 = 2511
Step 32: 2511 + 81 = 2592
Step 33: 2592 + 81 = 2673
Step 34: 2673 + 81 = 2754
Step 35: 2754 + 81 = 2835
Step 36: 2835 + 81 = 2916
Step 37: 2916 + 81 = 2997
Step 38: 2997 + 81 = 3078
Step 39: 3078 + 81 = 3159
Step 40: 3159 + 81 = 3240
Step 41: 3240 + 81 = 3321
Step 42: 3321 + 81 = 3402
Step 43: 3402 + 81 = 3483
Step 44: 3483 + 81 = 3564
Step 45: 3564 + 81 = 3645
Step 46: 3645 + 81 = 3726
Step 47: 3726 + 81 = 3807
Step 48: 3807 + 81 = 3888
Step 49: 3888 + 81 = 3969
Step 50: 3969 + 81 = 4050
Step 51: 4050 + 81 = 4131
Step 52: 4131 + 81 = 4212
Step 53: 4212 + 81 = 4293
Step 54: 4293 + 81 = 4374
Step 55: 4374 + 81 = 4455
Step 56: 4455 + 81 = 4536
Step 57: 4536 + 81 = 4617
Step 58: 4617 + 81 = 4698
Step 59: 4698 + 81 = 4779
Step 60: 4779 + 81 = 4860
Step 61: 4860 + 81 = 4941
Step 62: 4941 + 81 = 5022
Step 63: 5022 + 81 = 5103
Step 64: 5103 + 81 = 5184
Step 65: 5184 + 81 = 5265
Step 66: 5265 + 81 = 5346
Step 67: 5346 + 81 = 5427
Step 68: 5427 + 81 = 5508
Step 69: 5508 + 81 = 5589
Step 70: 5589 + 81 = 5670
Step 71: 5670 + 81 = 5751
Step 72: 5751 + 81 = 5832
Step 73: 5832 + 81 = 5913
Step 74: 5913 + 81 = 5994
Step 75: 5994 + 81 = 6075
Step 76: 6075 + 81 = 6156
Step 77: 6156 + 81 = 6237
Step 78: 6237 + 81 = 6318
Step 79: 6318 + 81 = 6399
Step 80: 6399 + 81 = 6480
Step 81: 6480 + 81 = 6561
Step 82: 6561 + 81 = 6642
Step 83: 6642 + 81 = 6723
Step 84: 6723 + 81 = 6804
Step 85: 6804 + 81 = 6885
Step 86: 6885 + 81 = 6966
Step 87: 6966 + 81 = 7047
Step 88: 7047 + 81 = 7128
Step 89: 7128 + 81 = 7209
Step 90: 7209 + 81 = 7290
Step 91: 7290 + 81 = 7371
Step 92: 7371 + 81 = 7452
Step 93: 7452 + 81 = 7533
Step 94: 7533 + 81 = 7614
Step 95: 7614 + 81 = 7695
Step 96: 7695 + 81 = 7776
Step 97: 7776 + 81 = 7857
Step 98: 7857 + 81 = 7938
Step 99: 7938 + 81 = 8019
Step 100: 8019 + 81 = 8100
Step 101: 8100 + 81 = 8181
Step 102: 8181 + 81 = 8262
Step 103: 8262 + 81 = 8343
Step 104: 8343 + 81 = 8424
Step 105: 8424 + 81 = 8505
Step 106: 8505 + 81 = 8586
Step 107: 8586 + 81 = 8667
Step 108: 8667 + 81 = 8748
Step 109: 8748 + 81 = 8829
Step 110: 8829 + 81 = 8910
Step 111: 8910 + 81 = 8991
Step 112: 8991 + 81 = 9072
Step 113: 9072 + 81 = 9153
Step 114: 9153 + 81 = 9234
Step 115: 9234 + 81 = 9315
Step 116: 9315 + 81 = 9396
Step 117: 9396 + 81 = 9477
Step 118: 9477 + 81 = 9558
Step 119: 9558 + 81 = 9639
Step 120: 9639 + 81 = 9720
Step 121: 9720 + 81 = 9801
Step 122: 9801 + 81 = 9882
Step 123: 9882 + 81 = 9963
Step 124: 9963 + 81 = 10044
Step 125: 10044 + 81 = 10125
Step 126: 10125 + 81 = 10206
Step 127: 10206 + 81 = 10287
Step 128: 10287 + 81 = 10368
Step 129: 10368 + 81 = 10449
Step 130: 10449 + 81 = 10530
Step 131: 10530 + 81 = 10611
Step 132: 10611 + 81 = 10692
Step 133: 10692 + 81 = 10773
Step 134: 10773 + 81 = 10854
Step 135: 10854 + 81 = 10935
Step 136: 10935 + 81 = 11016
Step 137: 11016 + 81 = 11097
Step 138: 11097 + 81 = 11178
Step 139: 11178 + 81 = 11259
Step 140: 11259 + 81 = 11340
Step 141: 11340 + 81 = 11421
Step 142: 11421 + 81 = 11502
Step 143: 11502 + 81 = 11583
Step 144: 11583 + 81 = 11664
Step 145: 11664 + 81 = 11745
Step 146: 11745 + 81 = 11826
Step 147: 11826 + 81 = 11907
Step 148: 11907 + 81 = 11988
Step 149: 11988 + 81 = 12069
Step 150: 12069 + 81 = 12150
Step 151: 12150 + 81 = 12231
Step 152: 12231 + 81 = 12312
Step 153: 12312 + 81 = 12393
Step 154: 12393 + 81 = 12474
Step 155: 12474 + 81 = 12555
Step 156: 12555 + 81 = 12636
Step 157: 12636 + 81 = 12717
Step 158: 12717 + 81 = 12798
Step 159: 12798 + 81 = 12879
Step 160: 12879 + 81 = 12960
Step 161: 12960 + 81 = 13041
Step 162: 13041 + 81 = 13122
Step 163: 13122 + 81 = 13203
Step 164: 13203 + 81 = 13284
Step 165: 13284 + 81 = 13365
Step 166: 13365 + 81 = 13446
Step 167: 13446 + 81 = 13527
Step 168: 13527 + 81 = 13608
Step 169: 13608 + 81 = 13689
Step 170: 13689 + 81 = 13770
Step 171: 13770 + 81 = 13851
Step 172: 13851 + 81 = 13932
Step 173: 13932 + 81 = 14013
Step 174: 14013 + 81 = 14094
Step 175: 14094 + 81 = 14175
Step 176: 14175 + 81 = 14256
Step 177: 14256 + 81 = 14337
Step 178: 14337 + 81 = 14418
Step 179: 14418 + 81 = 14499
Step 180: 14499 + 81 = 14580
Step 181: 14580 + 81 = 14661
Step 182: 14661 + 81 = 14742
Step 183: 14742 + 81 = 14823
Step 184: 14823 + 81 = 14904
Step 185: 14904 + 81 = 14985
Step 186: 14985 + 81 = 15066
Step 187: 15066 + 81 = 15147
Step 188: 15147 + 81 = 15228
Step 189: 15228 + 81 = 15309
Step 190: 15309 + 81 = 15390
Step 191: 15390 + 81 = 15471
Step 192: 15471 + 81 = 15552
Step 193: 15552 + 81 = 15633
Step 194: 15633 + 81 = 15714
Step 195: 15714 + 81 = 15795
Step 196: 15795 + 81 = 15876
Step 197: 15876 + 81 = 15957
Step 198: 15957 + 81 = 16038
Step 199: 16038 + 81 = 16119
Step 200: 16119 + 81 = 16200
Step 201: 16200 + 81 = 16281
Step 202: 16281 + 81 = 16362
Step 203: 16362 + 81 = 16443
Step 204: 16443 + 81 = 16524
Step 205: 16524 + 81 = 16605
Step 206: 16605 + 81 = 16686
Step 207: 16686 + 81 = 16767
Step 208: 16767 + 81 = 16848
Step 209: 16848 + 81 = 16929
Step 210: 16929 + 81 = 17010
Step 211: 17010 + 81 = 17091
Step 212: 17091 + 81 = 17172
Step 213: 17172 + 81 = 17253
Step 214: 17253 + 81 = 17334
Step 215: 17334 + 81 = 17415
Step 216: 17415 + 81 = 17496
Step 217: 17496 + 81 = 17577
Step 218: 17577 + 81 = 17658
Step 219: 17658 + 81 = 17739
Step 220: 17739 + 81 = 17820
Step 221: 17820 + 81 = 17901
Step 222: 17901 + 81 = 17982
Step 223: 17982 + 81 = 18063
Step 224: 18063 + 81 = 18144
Step 225: 18144 + 81 = 18225
Step 226: 18225 + 81 = 18306
Step 227: 18306 + 81 = 18387
Step 228: 18387 + 81 = 18468
Step 229: 18468 + 81 = 18549
Step 230: 18549 + 81 = 18630
Step 231: 18630 + 81 = 18711
Step 232: 18711 + 81 = 18792
Step 233: 18792 + 81 = 18873
Step 234: 18873 + 81 = 18954
Step 235: 18954 + 81 = 19035
Step 236: 19035 + 81 = 19116
Step 237: 19116 + 81 = 19197
Step 238: 19197 + 81 = 19278
Step 239: 19278 + 81 = 19359
Step 240: 19359 + 81 = 19440
Step 241: 19440 + 81 = 19521
Step 242: 19521 + 81 = 19602
Step 243: 19602 + 81 = 19683
Step 244: 19683 + 81 = 19764
Step 245: 19764 + 81 = 19845
Step 246: 19845 + 81 = 19926
Step 247: 19926 + 81 = 20007
Step 248: 20007 + 81 = 20088
Step 249: 20088 + 81 = 20169
Step 250: 20169 + 81 = 20250
Step 251: 20250 + 81 = 20331
Step 252: 20331 + 81 = 20412
Step 253: 20412 + 81 = 20493
Step 254: 20493 + 81 = 20574
Step 255: 20574 + 81 = 20655
Step 256: 20655 + 81 = 20736
Step 257: 20736 + 81 = 20817
Step 258: 20817 + 81 = 20898
Step 259: 20898 + 81 = 20979
Step 260: 20979 + 81 = 21060
Step 261: 21060 + 81 = 21141
Step 262: 21141 + 81 = 21222
Step 263: 21222 + 81 = 21303
Step 264: 21303 + 81 = 21384
Step 265: 21384 + 81 = 21465
Step 266: 21465 + 81 = 21546
Step 267: 21546 + 81 = 21627
Step 268: 21627 + 81 = 21708
Step 269: 21708 + 81 = 21789
Step 270: 21789 + 81 = 21870
Step 271: 21870 + 81 = 21951
Step 272: 21951 + 81 = 22032
Step 273: 22032 + 81 = 22113
Step 274: 22113 + 81 = 22194
Step 275: 22194 + 81 = 22275
Step 276: 22275 + 81 = 22356
Step 277: 22356 + 81 = 22437
Step 278: 22437 + 81 = 22518
Step 279: 22518 + 81 = 22599
Step 280: 22599 + 81 = 22680
Step 281: 22680 + 81 = 22761
Step 282: 22761 + 81 = 22842
Step 283: 22842 + 81 = 22923
Step 284: 22923 + 81 = 23004
Step 285: 23004 + 81 = 23085
Step 286: 23085 + 81 = 23166
Step 287: 23166 + 81 = 23247
Step 288: 23247 + 81 = 23328
Step 289: 23328 + 81 = 23409
Step 290: 23409 + 81 = 23490
Step 291: 23490 + 81 = 23571
Step 292: 23571 + 81 = 23652
Step 293: 23652 + 81 = 23733
Step 294: 23733 + 81 = 23814
Step 295: 23814 + 81 = 23895
Step 296: 23895 + 81 = 23976
Step 297: 23976 + 81 = 24057
Step 298: 24057 + 81 = 24138
Step 299: 24138 + 81 = 24219
Step 300: 24219 + 81 = 24300
Step 301: 24300 + 81 = 24381
Step 302: 24381 + 81 = 24462
Step 303: 24462 + 81 = 24543
Step 304: 24543 + 81 = 24624
Step 305: 24624 + 81 = 24705
Step 306: 24705 + 81 = 24786
Step 307: 24786 + 81 = 24867
Step 308: 24867 + 81 = 24948
Step 309: 24948 + 81 = 25029
Step 310: 25029 + 81 = 25110
Step 311: 25110 + 81 = 25191
Step 312: 25191 + 81 = 25272
Step 313: 25272 + 81 = 25353
Step 314: 25353 + 81 = 25434
Step 315: 25434 + 81 = 25515
Step 316: 25515 + 81 = 25596
Step 317: 25596 + 81 = 25677
Step 318: 25677 + 81 = 25758
Step 319: 25758 + 81 = 25839
Step 320: 25839 + 81 = 25920
Step 321: 25920 + 81 = 26001
Step 322: 26001 + 81 = 26082
Step 323: 26082 + 81 = 26163
Step 324: 26163 + 81 = 26244
Step 325: 26244 + 81 = 26325
Step 326: 26325 + 81 = 26406
Step 327: 26406 + 81 = 26487
Step 328: 26487 + 81 = 26568
Step 329: 26568 + 81 = 26649
Step 330: 26649 + 81 = 26730
Step 331: 26730 + 81 = 26811
Step 332: 26811 + 81 = 26892
Step 333: 26892 + 81 = 26973
Step 334: 26973 + 81 = 27054
Step 335: 27054 + 81 = 27135
Step 336: 27135 + 81 = 27216
Step 337: 27216 + 81 = 27297
Step 338: 27297 + 81 = 27378
Step 339: 27378 + 81 = 27459
Step 340: 27459 + 81 = 27540
Step 341: 27540 + 81 = 27621
Step 342: 27621 + 81 = 27702
Step 343: 27702 + 81 = 27783
Step 344: 27783 + 81 = 27864
Step 345: 27864 + 81 = 27945
Step 346: 27945 + 81 = 28026
Step 347: 28026 + 81 = 28107
Step 348: 28107 + 81 = 28188
Step 349: 28188 + 81 = 28269
Step 350: 28269 + 81 = 28350
Step 351: 28350 + 81 = 28431
Step 352: 28431 + 81 = 28512
Step 353: 28512 + 81 = 28593
Step 354: 28593 + 81 = 28674
Step 355: 28674 + 81 = 28755
Step 356: 28755 + 81 = 28836
Step 357: 28836 + 81 = 28917
Step 358: 28917 + 81 = 28998

So, 81*358 = 28998