OK, let's work through this together. We're starting with 987 and we're going to multiply it by 77, which means we add 987 to itself 77 times.
Step 1: 0 + 987 = 987
Step 2: 987 + 987 = 1974
Step 3: 1974 + 987 = 2961
Step 4: 2961 + 987 = 3948
Step 5: 3948 + 987 = 4935
Step 6: 4935 + 987 = 5922
Step 7: 5922 + 987 = 6909
Step 8: 6909 + 987 = 7896
Step 9: 7896 + 987 = 8883
Step 10: 8883 + 987 = 9870
Step 11: 9870 + 987 = 10857
Step 12: 10857 + 987 = 11844
Step 13: 11844 + 987 = 12831
Step 14: 12831 + 987 = 13818
Step 15: 13818 + 987 = 14805
Step 16: 14805 + 987 = 15792
Step 17: 15792 + 987 = 16779
Step 18: 16779 + 987 = 17766
Step 19: 17766 + 987 = 18753
Step 20: 18753 + 987 = 19740
Step 21: 19740 + 987 = 20727
Step 22: 20727 + 987 = 21714
Step 23: 21714 + 987 = 22701
Step 24: 22701 + 987 = 23688
Step 25: 23688 + 987 = 24675
Step 26: 24675 + 987 = 25662
Step 27: 25662 + 987 = 26649
Step 28: 26649 + 987 = 27636
Step 29: 27636 + 987 = 28623
Step 30: 28623 + 987 = 29610
Step 31: 29610 + 987 = 30597
Step 32: 30597 + 987 = 31584
Step 33: 31584 + 987 = 32571
Step 34: 32571 + 987 = 33558
Step 35: 33558 + 987 = 34545
Step 36: 34545 + 987 = 35532
Step 37: 35532 + 987 = 36519
Step 38: 36519 + 987 = 37506
Step 39: 37506 + 987 = 38493
Step 40: 38493 + 987 = 39480
Step 41: 39480 + 987 = 40467
Step 42: 40467 + 987 = 41454
Step 43: 41454 + 987 = 42441
Step 44: 42441 + 987 = 43428
Step 45: 43428 + 987 = 44415
Step 46: 44415 + 987 = 45402
Step 47: 45402 + 987 = 46389
Step 48: 46389 + 987 = 47376
Step 49: 47376 + 987 = 48363
Step 50: 48363 + 987 = 49350
Step 51: 49350 + 987 = 50337
Step 52: 50337 + 987 = 51324
Step 53: 51324 + 987 = 52311
Step 54: 52311 + 987 = 53298
Step 55: 53298 + 987 = 54285
Step 56: 54285 + 987 = 55272
Step 57: 55272 + 987 = 56259
Step 58: 56259 + 987 = 57246
Step 59: 57246 + 987 = 58233
Step 60: 58233 + 987 = 59220
Step 61: 59220 + 987 = 60207
Step 62: 60207 + 987 = 61194
Step 63: 61194 + 987 = 62181
Step 64: 62181 + 987 = 63168
Step 65: 63168 + 987 = 64155
Step 66: 64155 + 987 = 65142
Step 67: 65142 + 987 = 66129
Step 68: 66129 + 987 = 67116
Step 69: 67116 + 987 = 68103
Step 70: 68103 + 987 = 69090
Step 71: 69090 + 987 = 70077
Step 72: 70077 + 987 = 71064
Step 73: 71064 + 987 = 72051
Step 74: 72051 + 987 = 73038
Step 75: 73038 + 987 = 74025
Step 76: 74025 + 987 = 75012
Step 77: 75012 + 987 = 75999

So, 987*77 = 75999