OK, let's work through this together. We're starting with 663 and we're going to multiply it by 107, which means we add 663 to itself 107 times.
Step 1: 0 + 663 = 663
Step 2: 663 + 663 = 1326
Step 3: 1326 + 663 = 1989
Step 4: 1989 + 663 = 2652
Step 5: 2652 + 663 = 3315
Step 6: 3315 + 663 = 3978
Step 7: 3978 + 663 = 4641
Step 8: 4641 + 663 = 5304
Step 9: 5304 + 663 = 5967
Step 10: 5967 + 663 = 6630
Step 11: 6630 + 663 = 7293
Step 12: 7293 + 663 = 7956
Step 13: 7956 + 663 = 8619
Step 14: 8619 + 663 = 9282
Step 15: 9282 + 663 = 9945
Step 16: 9945 + 663 = 10608
Step 17: 10608 + 663 = 11271
Step 18: 11271 + 663 = 11934
Step 19: 11934 + 663 = 12597
Step 20: 12597 + 663 = 13260
Step 21: 13260 + 663 = 13923
Step 22: 13923 + 663 = 14586
Step 23: 14586 + 663 = 15249
Step 24: 15249 + 663 = 15912
Step 25: 15912 + 663 = 16575
Step 26: 16575 + 663 = 17238
Step 27: 17238 + 663 = 17901
Step 28: 17901 + 663 = 18564
Step 29: 18564 + 663 = 19227
Step 30: 19227 + 663 = 19890
Step 31: 19890 + 663 = 20553
Step 32: 20553 + 663 = 21216
Step 33: 21216 + 663 = 21879
Step 34: 21879 + 663 = 22542
Step 35: 22542 + 663 = 23205
Step 36: 23205 + 663 = 23868
Step 37: 23868 + 663 = 24531
Step 38: 24531 + 663 = 25194
Step 39: 25194 + 663 = 25857
Step 40: 25857 + 663 = 26520
Step 41: 26520 + 663 = 27183
Step 42: 27183 + 663 = 27846
Step 43: 27846 + 663 = 28509
Step 44: 28509 + 663 = 29172
Step 45: 29172 + 663 = 29835
Step 46: 29835 + 663 = 30498
Step 47: 30498 + 663 = 31161
Step 48: 31161 + 663 = 31824
Step 49: 31824 + 663 = 32487
Step 50: 32487 + 663 = 33150
Step 51: 33150 + 663 = 33813
Step 52: 33813 + 663 = 34476
Step 53: 34476 + 663 = 35139
Step 54: 35139 + 663 = 35802
Step 55: 35802 + 663 = 36465
Step 56: 36465 + 663 = 37128
Step 57: 37128 + 663 = 37791
Step 58: 37791 + 663 = 38454
Step 59: 38454 + 663 = 39117
Step 60: 39117 + 663 = 39780
Step 61: 39780 + 663 = 40443
Step 62: 40443 + 663 = 41106
Step 63: 41106 + 663 = 41769
Step 64: 41769 + 663 = 42432
Step 65: 42432 + 663 = 43095
Step 66: 43095 + 663 = 43758
Step 67: 43758 + 663 = 44421
Step 68: 44421 + 663 = 45084
Step 69: 45084 + 663 = 45747
Step 70: 45747 + 663 = 46410
Step 71: 46410 + 663 = 47073
Step 72: 47073 + 663 = 47736
Step 73: 47736 + 663 = 48399
Step 74: 48399 + 663 = 49062
Step 75: 49062 + 663 = 49725
Step 76: 49725 + 663 = 50388
Step 77: 50388 + 663 = 51051
Step 78: 51051 + 663 = 51714
Step 79: 51714 + 663 = 52377
Step 80: 52377 + 663 = 53040
Step 81: 53040 + 663 = 53703
Step 82: 53703 + 663 = 54366
Step 83: 54366 + 663 = 55029
Step 84: 55029 + 663 = 55692
Step 85: 55692 + 663 = 56355
Step 86: 56355 + 663 = 57018
Step 87: 57018 + 663 = 57681
Step 88: 57681 + 663 = 58344
Step 89: 58344 + 663 = 59007
Step 90: 59007 + 663 = 59670
Step 91: 59670 + 663 = 60333
Step 92: 60333 + 663 = 60996
Step 93: 60996 + 663 = 61659
Step 94: 61659 + 663 = 62322
Step 95: 62322 + 663 = 62985
Step 96: 62985 + 663 = 63648
Step 97: 63648 + 663 = 64311
Step 98: 64311 + 663 = 64974
Step 99: 64974 + 663 = 65637
Step 100: 65637 + 663 = 66300
Step 101: 66300 + 663 = 66963
Step 102: 66963 + 663 = 67626
Step 103: 67626 + 663 = 68289
Step 104: 68289 + 663 = 68952
Step 105: 68952 + 663 = 69615
Step 106: 69615 + 663 = 70278
Step 107: 70278 + 663 = 70941

So, 663*107 = 70941