Alright, let's solve this math problem step by step. First, we have the number 646. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 105. So, we're going to take the number 646 and add it to itself 105 times.
Step 1: 0 + 646 = 646
Step 2: 646 + 646 = 1292
Step 3: 1292 + 646 = 1938
Step 4: 1938 + 646 = 2584
Step 5: 2584 + 646 = 3230
Step 6: 3230 + 646 = 3876
Step 7: 3876 + 646 = 4522
Step 8: 4522 + 646 = 5168
Step 9: 5168 + 646 = 5814
Step 10: 5814 + 646 = 6460
Step 11: 6460 + 646 = 7106
Step 12: 7106 + 646 = 7752
Step 13: 7752 + 646 = 8398
Step 14: 8398 + 646 = 9044
Step 15: 9044 + 646 = 9690
Step 16: 9690 + 646 = 10336
Step 17: 10336 + 646 = 10982
Step 18: 10982 + 646 = 11628
Step 19: 11628 + 646 = 12274
Step 20: 12274 + 646 = 12920
Step 21: 12920 + 646 = 13566
Step 22: 13566 + 646 = 14212
Step 23: 14212 + 646 = 14858
Step 24: 14858 + 646 = 15504
Step 25: 15504 + 646 = 16150
Step 26: 16150 + 646 = 16796
Step 27: 16796 + 646 = 17442
Step 28: 17442 + 646 = 18088
Step 29: 18088 + 646 = 18734
Step 30: 18734 + 646 = 19380
Step 31: 19380 + 646 = 20026
Step 32: 20026 + 646 = 20672
Step 33: 20672 + 646 = 21318
Step 34: 21318 + 646 = 21964
Step 35: 21964 + 646 = 22610
Step 36: 22610 + 646 = 23256
Step 37: 23256 + 646 = 23902
Step 38: 23902 + 646 = 24548
Step 39: 24548 + 646 = 25194
Step 40: 25194 + 646 = 25840
Step 41: 25840 + 646 = 26486
Step 42: 26486 + 646 = 27132
Step 43: 27132 + 646 = 27778
Step 44: 27778 + 646 = 28424
Step 45: 28424 + 646 = 29070
Step 46: 29070 + 646 = 29716
Step 47: 29716 + 646 = 30362
Step 48: 30362 + 646 = 31008
Step 49: 31008 + 646 = 31654
Step 50: 31654 + 646 = 32300
Step 51: 32300 + 646 = 32946
Step 52: 32946 + 646 = 33592
Step 53: 33592 + 646 = 34238
Step 54: 34238 + 646 = 34884
Step 55: 34884 + 646 = 35530
Step 56: 35530 + 646 = 36176
Step 57: 36176 + 646 = 36822
Step 58: 36822 + 646 = 37468
Step 59: 37468 + 646 = 38114
Step 60: 38114 + 646 = 38760
Step 61: 38760 + 646 = 39406
Step 62: 39406 + 646 = 40052
Step 63: 40052 + 646 = 40698
Step 64: 40698 + 646 = 41344
Step 65: 41344 + 646 = 41990
Step 66: 41990 + 646 = 42636
Step 67: 42636 + 646 = 43282
Step 68: 43282 + 646 = 43928
Step 69: 43928 + 646 = 44574
Step 70: 44574 + 646 = 45220
Step 71: 45220 + 646 = 45866
Step 72: 45866 + 646 = 46512
Step 73: 46512 + 646 = 47158
Step 74: 47158 + 646 = 47804
Step 75: 47804 + 646 = 48450
Step 76: 48450 + 646 = 49096
Step 77: 49096 + 646 = 49742
Step 78: 49742 + 646 = 50388
Step 79: 50388 + 646 = 51034
Step 80: 51034 + 646 = 51680
Step 81: 51680 + 646 = 52326
Step 82: 52326 + 646 = 52972
Step 83: 52972 + 646 = 53618
Step 84: 53618 + 646 = 54264
Step 85: 54264 + 646 = 54910
Step 86: 54910 + 646 = 55556
Step 87: 55556 + 646 = 56202
Step 88: 56202 + 646 = 56848
Step 89: 56848 + 646 = 57494
Step 90: 57494 + 646 = 58140
Step 91: 58140 + 646 = 58786
Step 92: 58786 + 646 = 59432
Step 93: 59432 + 646 = 60078
Step 94: 60078 + 646 = 60724
Step 95: 60724 + 646 = 61370
Step 96: 61370 + 646 = 62016
Step 97: 62016 + 646 = 62662
Step 98: 62662 + 646 = 63308
Step 99: 63308 + 646 = 63954
Step 100: 63954 + 646 = 64600
Step 101: 64600 + 646 = 65246
Step 102: 65246 + 646 = 65892
Step 103: 65892 + 646 = 66538
Step 104: 66538 + 646 = 67184
Step 105: 67184 + 646 = 67830

So, 646*105 = 67830