OK, let's work through this together. We're starting with 771 and we're going to multiply it by 83, which means we add 771 to itself 83 times.
Step 1: 0 + 771 = 771
Step 2: 771 + 771 = 1542
Step 3: 1542 + 771 = 2313
Step 4: 2313 + 771 = 3084
Step 5: 3084 + 771 = 3855
Step 6: 3855 + 771 = 4626
Step 7: 4626 + 771 = 5397
Step 8: 5397 + 771 = 6168
Step 9: 6168 + 771 = 6939
Step 10: 6939 + 771 = 7710
Step 11: 7710 + 771 = 8481
Step 12: 8481 + 771 = 9252
Step 13: 9252 + 771 = 10023
Step 14: 10023 + 771 = 10794
Step 15: 10794 + 771 = 11565
Step 16: 11565 + 771 = 12336
Step 17: 12336 + 771 = 13107
Step 18: 13107 + 771 = 13878
Step 19: 13878 + 771 = 14649
Step 20: 14649 + 771 = 15420
Step 21: 15420 + 771 = 16191
Step 22: 16191 + 771 = 16962
Step 23: 16962 + 771 = 17733
Step 24: 17733 + 771 = 18504
Step 25: 18504 + 771 = 19275
Step 26: 19275 + 771 = 20046
Step 27: 20046 + 771 = 20817
Step 28: 20817 + 771 = 21588
Step 29: 21588 + 771 = 22359
Step 30: 22359 + 771 = 23130
Step 31: 23130 + 771 = 23901
Step 32: 23901 + 771 = 24672
Step 33: 24672 + 771 = 25443
Step 34: 25443 + 771 = 26214
Step 35: 26214 + 771 = 26985
Step 36: 26985 + 771 = 27756
Step 37: 27756 + 771 = 28527
Step 38: 28527 + 771 = 29298
Step 39: 29298 + 771 = 30069
Step 40: 30069 + 771 = 30840
Step 41: 30840 + 771 = 31611
Step 42: 31611 + 771 = 32382
Step 43: 32382 + 771 = 33153
Step 44: 33153 + 771 = 33924
Step 45: 33924 + 771 = 34695
Step 46: 34695 + 771 = 35466
Step 47: 35466 + 771 = 36237
Step 48: 36237 + 771 = 37008
Step 49: 37008 + 771 = 37779
Step 50: 37779 + 771 = 38550
Step 51: 38550 + 771 = 39321
Step 52: 39321 + 771 = 40092
Step 53: 40092 + 771 = 40863
Step 54: 40863 + 771 = 41634
Step 55: 41634 + 771 = 42405
Step 56: 42405 + 771 = 43176
Step 57: 43176 + 771 = 43947
Step 58: 43947 + 771 = 44718
Step 59: 44718 + 771 = 45489
Step 60: 45489 + 771 = 46260
Step 61: 46260 + 771 = 47031
Step 62: 47031 + 771 = 47802
Step 63: 47802 + 771 = 48573
Step 64: 48573 + 771 = 49344
Step 65: 49344 + 771 = 50115
Step 66: 50115 + 771 = 50886
Step 67: 50886 + 771 = 51657
Step 68: 51657 + 771 = 52428
Step 69: 52428 + 771 = 53199
Step 70: 53199 + 771 = 53970
Step 71: 53970 + 771 = 54741
Step 72: 54741 + 771 = 55512
Step 73: 55512 + 771 = 56283
Step 74: 56283 + 771 = 57054
Step 75: 57054 + 771 = 57825
Step 76: 57825 + 771 = 58596
Step 77: 58596 + 771 = 59367
Step 78: 59367 + 771 = 60138
Step 79: 60138 + 771 = 60909
Step 80: 60909 + 771 = 61680
Step 81: 61680 + 771 = 62451
Step 82: 62451 + 771 = 63222
Step 83: 63222 + 771 = 63993

So, 771*83 = 63993