OK, let's work through this together. We're starting with 765 and we're going to multiply it by 107, which means we add 765 to itself 107 times.
Step 1: 0 + 765 = 765
Step 2: 765 + 765 = 1530
Step 3: 1530 + 765 = 2295
Step 4: 2295 + 765 = 3060
Step 5: 3060 + 765 = 3825
Step 6: 3825 + 765 = 4590
Step 7: 4590 + 765 = 5355
Step 8: 5355 + 765 = 6120
Step 9: 6120 + 765 = 6885
Step 10: 6885 + 765 = 7650
Step 11: 7650 + 765 = 8415
Step 12: 8415 + 765 = 9180
Step 13: 9180 + 765 = 9945
Step 14: 9945 + 765 = 10710
Step 15: 10710 + 765 = 11475
Step 16: 11475 + 765 = 12240
Step 17: 12240 + 765 = 13005
Step 18: 13005 + 765 = 13770
Step 19: 13770 + 765 = 14535
Step 20: 14535 + 765 = 15300
Step 21: 15300 + 765 = 16065
Step 22: 16065 + 765 = 16830
Step 23: 16830 + 765 = 17595
Step 24: 17595 + 765 = 18360
Step 25: 18360 + 765 = 19125
Step 26: 19125 + 765 = 19890
Step 27: 19890 + 765 = 20655
Step 28: 20655 + 765 = 21420
Step 29: 21420 + 765 = 22185
Step 30: 22185 + 765 = 22950
Step 31: 22950 + 765 = 23715
Step 32: 23715 + 765 = 24480
Step 33: 24480 + 765 = 25245
Step 34: 25245 + 765 = 26010
Step 35: 26010 + 765 = 26775
Step 36: 26775 + 765 = 27540
Step 37: 27540 + 765 = 28305
Step 38: 28305 + 765 = 29070
Step 39: 29070 + 765 = 29835
Step 40: 29835 + 765 = 30600
Step 41: 30600 + 765 = 31365
Step 42: 31365 + 765 = 32130
Step 43: 32130 + 765 = 32895
Step 44: 32895 + 765 = 33660
Step 45: 33660 + 765 = 34425
Step 46: 34425 + 765 = 35190
Step 47: 35190 + 765 = 35955
Step 48: 35955 + 765 = 36720
Step 49: 36720 + 765 = 37485
Step 50: 37485 + 765 = 38250
Step 51: 38250 + 765 = 39015
Step 52: 39015 + 765 = 39780
Step 53: 39780 + 765 = 40545
Step 54: 40545 + 765 = 41310
Step 55: 41310 + 765 = 42075
Step 56: 42075 + 765 = 42840
Step 57: 42840 + 765 = 43605
Step 58: 43605 + 765 = 44370
Step 59: 44370 + 765 = 45135
Step 60: 45135 + 765 = 45900
Step 61: 45900 + 765 = 46665
Step 62: 46665 + 765 = 47430
Step 63: 47430 + 765 = 48195
Step 64: 48195 + 765 = 48960
Step 65: 48960 + 765 = 49725
Step 66: 49725 + 765 = 50490
Step 67: 50490 + 765 = 51255
Step 68: 51255 + 765 = 52020
Step 69: 52020 + 765 = 52785
Step 70: 52785 + 765 = 53550
Step 71: 53550 + 765 = 54315
Step 72: 54315 + 765 = 55080
Step 73: 55080 + 765 = 55845
Step 74: 55845 + 765 = 56610
Step 75: 56610 + 765 = 57375
Step 76: 57375 + 765 = 58140
Step 77: 58140 + 765 = 58905
Step 78: 58905 + 765 = 59670
Step 79: 59670 + 765 = 60435
Step 80: 60435 + 765 = 61200
Step 81: 61200 + 765 = 61965
Step 82: 61965 + 765 = 62730
Step 83: 62730 + 765 = 63495
Step 84: 63495 + 765 = 64260
Step 85: 64260 + 765 = 65025
Step 86: 65025 + 765 = 65790
Step 87: 65790 + 765 = 66555
Step 88: 66555 + 765 = 67320
Step 89: 67320 + 765 = 68085
Step 90: 68085 + 765 = 68850
Step 91: 68850 + 765 = 69615
Step 92: 69615 + 765 = 70380
Step 93: 70380 + 765 = 71145
Step 94: 71145 + 765 = 71910
Step 95: 71910 + 765 = 72675
Step 96: 72675 + 765 = 73440
Step 97: 73440 + 765 = 74205
Step 98: 74205 + 765 = 74970
Step 99: 74970 + 765 = 75735
Step 100: 75735 + 765 = 76500
Step 101: 76500 + 765 = 77265
Step 102: 77265 + 765 = 78030
Step 103: 78030 + 765 = 78795
Step 104: 78795 + 765 = 79560
Step 105: 79560 + 765 = 80325
Step 106: 80325 + 765 = 81090
Step 107: 81090 + 765 = 81855

So, 765*107 = 81855