OK, let's crack this. We're given 781 and our task is to multiply it by 77. Essentially, we'll be adding 781 to itself 77 times.
Step 1: 0 + 781 = 781
Step 2: 781 + 781 = 1562
Step 3: 1562 + 781 = 2343
Step 4: 2343 + 781 = 3124
Step 5: 3124 + 781 = 3905
Step 6: 3905 + 781 = 4686
Step 7: 4686 + 781 = 5467
Step 8: 5467 + 781 = 6248
Step 9: 6248 + 781 = 7029
Step 10: 7029 + 781 = 7810
Step 11: 7810 + 781 = 8591
Step 12: 8591 + 781 = 9372
Step 13: 9372 + 781 = 10153
Step 14: 10153 + 781 = 10934
Step 15: 10934 + 781 = 11715
Step 16: 11715 + 781 = 12496
Step 17: 12496 + 781 = 13277
Step 18: 13277 + 781 = 14058
Step 19: 14058 + 781 = 14839
Step 20: 14839 + 781 = 15620
Step 21: 15620 + 781 = 16401
Step 22: 16401 + 781 = 17182
Step 23: 17182 + 781 = 17963
Step 24: 17963 + 781 = 18744
Step 25: 18744 + 781 = 19525
Step 26: 19525 + 781 = 20306
Step 27: 20306 + 781 = 21087
Step 28: 21087 + 781 = 21868
Step 29: 21868 + 781 = 22649
Step 30: 22649 + 781 = 23430
Step 31: 23430 + 781 = 24211
Step 32: 24211 + 781 = 24992
Step 33: 24992 + 781 = 25773
Step 34: 25773 + 781 = 26554
Step 35: 26554 + 781 = 27335
Step 36: 27335 + 781 = 28116
Step 37: 28116 + 781 = 28897
Step 38: 28897 + 781 = 29678
Step 39: 29678 + 781 = 30459
Step 40: 30459 + 781 = 31240
Step 41: 31240 + 781 = 32021
Step 42: 32021 + 781 = 32802
Step 43: 32802 + 781 = 33583
Step 44: 33583 + 781 = 34364
Step 45: 34364 + 781 = 35145
Step 46: 35145 + 781 = 35926
Step 47: 35926 + 781 = 36707
Step 48: 36707 + 781 = 37488
Step 49: 37488 + 781 = 38269
Step 50: 38269 + 781 = 39050
Step 51: 39050 + 781 = 39831
Step 52: 39831 + 781 = 40612
Step 53: 40612 + 781 = 41393
Step 54: 41393 + 781 = 42174
Step 55: 42174 + 781 = 42955
Step 56: 42955 + 781 = 43736
Step 57: 43736 + 781 = 44517
Step 58: 44517 + 781 = 45298
Step 59: 45298 + 781 = 46079
Step 60: 46079 + 781 = 46860
Step 61: 46860 + 781 = 47641
Step 62: 47641 + 781 = 48422
Step 63: 48422 + 781 = 49203
Step 64: 49203 + 781 = 49984
Step 65: 49984 + 781 = 50765
Step 66: 50765 + 781 = 51546
Step 67: 51546 + 781 = 52327
Step 68: 52327 + 781 = 53108
Step 69: 53108 + 781 = 53889
Step 70: 53889 + 781 = 54670
Step 71: 54670 + 781 = 55451
Step 72: 55451 + 781 = 56232
Step 73: 56232 + 781 = 57013
Step 74: 57013 + 781 = 57794
Step 75: 57794 + 781 = 58575
Step 76: 58575 + 781 = 59356
Step 77: 59356 + 781 = 60137

So, 781*77 = 60137