Let's roll up our sleeves and solve this. We have 911 and we're going to multiply it by 84, essentially adding 911 to itself 84 times.
Step 1: 0 + 911 = 911
Step 2: 911 + 911 = 1822
Step 3: 1822 + 911 = 2733
Step 4: 2733 + 911 = 3644
Step 5: 3644 + 911 = 4555
Step 6: 4555 + 911 = 5466
Step 7: 5466 + 911 = 6377
Step 8: 6377 + 911 = 7288
Step 9: 7288 + 911 = 8199
Step 10: 8199 + 911 = 9110
Step 11: 9110 + 911 = 10021
Step 12: 10021 + 911 = 10932
Step 13: 10932 + 911 = 11843
Step 14: 11843 + 911 = 12754
Step 15: 12754 + 911 = 13665
Step 16: 13665 + 911 = 14576
Step 17: 14576 + 911 = 15487
Step 18: 15487 + 911 = 16398
Step 19: 16398 + 911 = 17309
Step 20: 17309 + 911 = 18220
Step 21: 18220 + 911 = 19131
Step 22: 19131 + 911 = 20042
Step 23: 20042 + 911 = 20953
Step 24: 20953 + 911 = 21864
Step 25: 21864 + 911 = 22775
Step 26: 22775 + 911 = 23686
Step 27: 23686 + 911 = 24597
Step 28: 24597 + 911 = 25508
Step 29: 25508 + 911 = 26419
Step 30: 26419 + 911 = 27330
Step 31: 27330 + 911 = 28241
Step 32: 28241 + 911 = 29152
Step 33: 29152 + 911 = 30063
Step 34: 30063 + 911 = 30974
Step 35: 30974 + 911 = 31885
Step 36: 31885 + 911 = 32796
Step 37: 32796 + 911 = 33707
Step 38: 33707 + 911 = 34618
Step 39: 34618 + 911 = 35529
Step 40: 35529 + 911 = 36440
Step 41: 36440 + 911 = 37351
Step 42: 37351 + 911 = 38262
Step 43: 38262 + 911 = 39173
Step 44: 39173 + 911 = 40084
Step 45: 40084 + 911 = 40995
Step 46: 40995 + 911 = 41906
Step 47: 41906 + 911 = 42817
Step 48: 42817 + 911 = 43728
Step 49: 43728 + 911 = 44639
Step 50: 44639 + 911 = 45550
Step 51: 45550 + 911 = 46461
Step 52: 46461 + 911 = 47372
Step 53: 47372 + 911 = 48283
Step 54: 48283 + 911 = 49194
Step 55: 49194 + 911 = 50105
Step 56: 50105 + 911 = 51016
Step 57: 51016 + 911 = 51927
Step 58: 51927 + 911 = 52838
Step 59: 52838 + 911 = 53749
Step 60: 53749 + 911 = 54660
Step 61: 54660 + 911 = 55571
Step 62: 55571 + 911 = 56482
Step 63: 56482 + 911 = 57393
Step 64: 57393 + 911 = 58304
Step 65: 58304 + 911 = 59215
Step 66: 59215 + 911 = 60126
Step 67: 60126 + 911 = 61037
Step 68: 61037 + 911 = 61948
Step 69: 61948 + 911 = 62859
Step 70: 62859 + 911 = 63770
Step 71: 63770 + 911 = 64681
Step 72: 64681 + 911 = 65592
Step 73: 65592 + 911 = 66503
Step 74: 66503 + 911 = 67414
Step 75: 67414 + 911 = 68325
Step 76: 68325 + 911 = 69236
Step 77: 69236 + 911 = 70147
Step 78: 70147 + 911 = 71058
Step 79: 71058 + 911 = 71969
Step 80: 71969 + 911 = 72880
Step 81: 72880 + 911 = 73791
Step 82: 73791 + 911 = 74702
Step 83: 74702 + 911 = 75613
Step 84: 75613 + 911 = 76524

So, 911*84 = 76524