OK, let's crack this. We're given 587 and our task is to multiply it by 99. Essentially, we'll be adding 587 to itself 99 times.
Step 1: 0 + 587 = 587
Step 2: 587 + 587 = 1174
Step 3: 1174 + 587 = 1761
Step 4: 1761 + 587 = 2348
Step 5: 2348 + 587 = 2935
Step 6: 2935 + 587 = 3522
Step 7: 3522 + 587 = 4109
Step 8: 4109 + 587 = 4696
Step 9: 4696 + 587 = 5283
Step 10: 5283 + 587 = 5870
Step 11: 5870 + 587 = 6457
Step 12: 6457 + 587 = 7044
Step 13: 7044 + 587 = 7631
Step 14: 7631 + 587 = 8218
Step 15: 8218 + 587 = 8805
Step 16: 8805 + 587 = 9392
Step 17: 9392 + 587 = 9979
Step 18: 9979 + 587 = 10566
Step 19: 10566 + 587 = 11153
Step 20: 11153 + 587 = 11740
Step 21: 11740 + 587 = 12327
Step 22: 12327 + 587 = 12914
Step 23: 12914 + 587 = 13501
Step 24: 13501 + 587 = 14088
Step 25: 14088 + 587 = 14675
Step 26: 14675 + 587 = 15262
Step 27: 15262 + 587 = 15849
Step 28: 15849 + 587 = 16436
Step 29: 16436 + 587 = 17023
Step 30: 17023 + 587 = 17610
Step 31: 17610 + 587 = 18197
Step 32: 18197 + 587 = 18784
Step 33: 18784 + 587 = 19371
Step 34: 19371 + 587 = 19958
Step 35: 19958 + 587 = 20545
Step 36: 20545 + 587 = 21132
Step 37: 21132 + 587 = 21719
Step 38: 21719 + 587 = 22306
Step 39: 22306 + 587 = 22893
Step 40: 22893 + 587 = 23480
Step 41: 23480 + 587 = 24067
Step 42: 24067 + 587 = 24654
Step 43: 24654 + 587 = 25241
Step 44: 25241 + 587 = 25828
Step 45: 25828 + 587 = 26415
Step 46: 26415 + 587 = 27002
Step 47: 27002 + 587 = 27589
Step 48: 27589 + 587 = 28176
Step 49: 28176 + 587 = 28763
Step 50: 28763 + 587 = 29350
Step 51: 29350 + 587 = 29937
Step 52: 29937 + 587 = 30524
Step 53: 30524 + 587 = 31111
Step 54: 31111 + 587 = 31698
Step 55: 31698 + 587 = 32285
Step 56: 32285 + 587 = 32872
Step 57: 32872 + 587 = 33459
Step 58: 33459 + 587 = 34046
Step 59: 34046 + 587 = 34633
Step 60: 34633 + 587 = 35220
Step 61: 35220 + 587 = 35807
Step 62: 35807 + 587 = 36394
Step 63: 36394 + 587 = 36981
Step 64: 36981 + 587 = 37568
Step 65: 37568 + 587 = 38155
Step 66: 38155 + 587 = 38742
Step 67: 38742 + 587 = 39329
Step 68: 39329 + 587 = 39916
Step 69: 39916 + 587 = 40503
Step 70: 40503 + 587 = 41090
Step 71: 41090 + 587 = 41677
Step 72: 41677 + 587 = 42264
Step 73: 42264 + 587 = 42851
Step 74: 42851 + 587 = 43438
Step 75: 43438 + 587 = 44025
Step 76: 44025 + 587 = 44612
Step 77: 44612 + 587 = 45199
Step 78: 45199 + 587 = 45786
Step 79: 45786 + 587 = 46373
Step 80: 46373 + 587 = 46960
Step 81: 46960 + 587 = 47547
Step 82: 47547 + 587 = 48134
Step 83: 48134 + 587 = 48721
Step 84: 48721 + 587 = 49308
Step 85: 49308 + 587 = 49895
Step 86: 49895 + 587 = 50482
Step 87: 50482 + 587 = 51069
Step 88: 51069 + 587 = 51656
Step 89: 51656 + 587 = 52243
Step 90: 52243 + 587 = 52830
Step 91: 52830 + 587 = 53417
Step 92: 53417 + 587 = 54004
Step 93: 54004 + 587 = 54591
Step 94: 54591 + 587 = 55178
Step 95: 55178 + 587 = 55765
Step 96: 55765 + 587 = 56352
Step 97: 56352 + 587 = 56939
Step 98: 56939 + 587 = 57526
Step 99: 57526 + 587 = 58113

So, 587*99 = 58113