OK, let's crack this. We're given 849 and our task is to multiply it by 105. Essentially, we'll be adding 849 to itself 105 times.
Step 1: 0 + 849 = 849
Step 2: 849 + 849 = 1698
Step 3: 1698 + 849 = 2547
Step 4: 2547 + 849 = 3396
Step 5: 3396 + 849 = 4245
Step 6: 4245 + 849 = 5094
Step 7: 5094 + 849 = 5943
Step 8: 5943 + 849 = 6792
Step 9: 6792 + 849 = 7641
Step 10: 7641 + 849 = 8490
Step 11: 8490 + 849 = 9339
Step 12: 9339 + 849 = 10188
Step 13: 10188 + 849 = 11037
Step 14: 11037 + 849 = 11886
Step 15: 11886 + 849 = 12735
Step 16: 12735 + 849 = 13584
Step 17: 13584 + 849 = 14433
Step 18: 14433 + 849 = 15282
Step 19: 15282 + 849 = 16131
Step 20: 16131 + 849 = 16980
Step 21: 16980 + 849 = 17829
Step 22: 17829 + 849 = 18678
Step 23: 18678 + 849 = 19527
Step 24: 19527 + 849 = 20376
Step 25: 20376 + 849 = 21225
Step 26: 21225 + 849 = 22074
Step 27: 22074 + 849 = 22923
Step 28: 22923 + 849 = 23772
Step 29: 23772 + 849 = 24621
Step 30: 24621 + 849 = 25470
Step 31: 25470 + 849 = 26319
Step 32: 26319 + 849 = 27168
Step 33: 27168 + 849 = 28017
Step 34: 28017 + 849 = 28866
Step 35: 28866 + 849 = 29715
Step 36: 29715 + 849 = 30564
Step 37: 30564 + 849 = 31413
Step 38: 31413 + 849 = 32262
Step 39: 32262 + 849 = 33111
Step 40: 33111 + 849 = 33960
Step 41: 33960 + 849 = 34809
Step 42: 34809 + 849 = 35658
Step 43: 35658 + 849 = 36507
Step 44: 36507 + 849 = 37356
Step 45: 37356 + 849 = 38205
Step 46: 38205 + 849 = 39054
Step 47: 39054 + 849 = 39903
Step 48: 39903 + 849 = 40752
Step 49: 40752 + 849 = 41601
Step 50: 41601 + 849 = 42450
Step 51: 42450 + 849 = 43299
Step 52: 43299 + 849 = 44148
Step 53: 44148 + 849 = 44997
Step 54: 44997 + 849 = 45846
Step 55: 45846 + 849 = 46695
Step 56: 46695 + 849 = 47544
Step 57: 47544 + 849 = 48393
Step 58: 48393 + 849 = 49242
Step 59: 49242 + 849 = 50091
Step 60: 50091 + 849 = 50940
Step 61: 50940 + 849 = 51789
Step 62: 51789 + 849 = 52638
Step 63: 52638 + 849 = 53487
Step 64: 53487 + 849 = 54336
Step 65: 54336 + 849 = 55185
Step 66: 55185 + 849 = 56034
Step 67: 56034 + 849 = 56883
Step 68: 56883 + 849 = 57732
Step 69: 57732 + 849 = 58581
Step 70: 58581 + 849 = 59430
Step 71: 59430 + 849 = 60279
Step 72: 60279 + 849 = 61128
Step 73: 61128 + 849 = 61977
Step 74: 61977 + 849 = 62826
Step 75: 62826 + 849 = 63675
Step 76: 63675 + 849 = 64524
Step 77: 64524 + 849 = 65373
Step 78: 65373 + 849 = 66222
Step 79: 66222 + 849 = 67071
Step 80: 67071 + 849 = 67920
Step 81: 67920 + 849 = 68769
Step 82: 68769 + 849 = 69618
Step 83: 69618 + 849 = 70467
Step 84: 70467 + 849 = 71316
Step 85: 71316 + 849 = 72165
Step 86: 72165 + 849 = 73014
Step 87: 73014 + 849 = 73863
Step 88: 73863 + 849 = 74712
Step 89: 74712 + 849 = 75561
Step 90: 75561 + 849 = 76410
Step 91: 76410 + 849 = 77259
Step 92: 77259 + 849 = 78108
Step 93: 78108 + 849 = 78957
Step 94: 78957 + 849 = 79806
Step 95: 79806 + 849 = 80655
Step 96: 80655 + 849 = 81504
Step 97: 81504 + 849 = 82353
Step 98: 82353 + 849 = 83202
Step 99: 83202 + 849 = 84051
Step 100: 84051 + 849 = 84900
Step 101: 84900 + 849 = 85749
Step 102: 85749 + 849 = 86598
Step 103: 86598 + 849 = 87447
Step 104: 87447 + 849 = 88296
Step 105: 88296 + 849 = 89145

So, 849*105 = 89145