Without delay, let's solve this. We've got 513 and we will be multiplying it by 158, that is, adding 513 to itself 158 times.
Step 1: 0 + 513 = 513
Step 2: 513 + 513 = 1026
Step 3: 1026 + 513 = 1539
Step 4: 1539 + 513 = 2052
Step 5: 2052 + 513 = 2565
Step 6: 2565 + 513 = 3078
Step 7: 3078 + 513 = 3591
Step 8: 3591 + 513 = 4104
Step 9: 4104 + 513 = 4617
Step 10: 4617 + 513 = 5130
Step 11: 5130 + 513 = 5643
Step 12: 5643 + 513 = 6156
Step 13: 6156 + 513 = 6669
Step 14: 6669 + 513 = 7182
Step 15: 7182 + 513 = 7695
Step 16: 7695 + 513 = 8208
Step 17: 8208 + 513 = 8721
Step 18: 8721 + 513 = 9234
Step 19: 9234 + 513 = 9747
Step 20: 9747 + 513 = 10260
Step 21: 10260 + 513 = 10773
Step 22: 10773 + 513 = 11286
Step 23: 11286 + 513 = 11799
Step 24: 11799 + 513 = 12312
Step 25: 12312 + 513 = 12825
Step 26: 12825 + 513 = 13338
Step 27: 13338 + 513 = 13851
Step 28: 13851 + 513 = 14364
Step 29: 14364 + 513 = 14877
Step 30: 14877 + 513 = 15390
Step 31: 15390 + 513 = 15903
Step 32: 15903 + 513 = 16416
Step 33: 16416 + 513 = 16929
Step 34: 16929 + 513 = 17442
Step 35: 17442 + 513 = 17955
Step 36: 17955 + 513 = 18468
Step 37: 18468 + 513 = 18981
Step 38: 18981 + 513 = 19494
Step 39: 19494 + 513 = 20007
Step 40: 20007 + 513 = 20520
Step 41: 20520 + 513 = 21033
Step 42: 21033 + 513 = 21546
Step 43: 21546 + 513 = 22059
Step 44: 22059 + 513 = 22572
Step 45: 22572 + 513 = 23085
Step 46: 23085 + 513 = 23598
Step 47: 23598 + 513 = 24111
Step 48: 24111 + 513 = 24624
Step 49: 24624 + 513 = 25137
Step 50: 25137 + 513 = 25650
Step 51: 25650 + 513 = 26163
Step 52: 26163 + 513 = 26676
Step 53: 26676 + 513 = 27189
Step 54: 27189 + 513 = 27702
Step 55: 27702 + 513 = 28215
Step 56: 28215 + 513 = 28728
Step 57: 28728 + 513 = 29241
Step 58: 29241 + 513 = 29754
Step 59: 29754 + 513 = 30267
Step 60: 30267 + 513 = 30780
Step 61: 30780 + 513 = 31293
Step 62: 31293 + 513 = 31806
Step 63: 31806 + 513 = 32319
Step 64: 32319 + 513 = 32832
Step 65: 32832 + 513 = 33345
Step 66: 33345 + 513 = 33858
Step 67: 33858 + 513 = 34371
Step 68: 34371 + 513 = 34884
Step 69: 34884 + 513 = 35397
Step 70: 35397 + 513 = 35910
Step 71: 35910 + 513 = 36423
Step 72: 36423 + 513 = 36936
Step 73: 36936 + 513 = 37449
Step 74: 37449 + 513 = 37962
Step 75: 37962 + 513 = 38475
Step 76: 38475 + 513 = 38988
Step 77: 38988 + 513 = 39501
Step 78: 39501 + 513 = 40014
Step 79: 40014 + 513 = 40527
Step 80: 40527 + 513 = 41040
Step 81: 41040 + 513 = 41553
Step 82: 41553 + 513 = 42066
Step 83: 42066 + 513 = 42579
Step 84: 42579 + 513 = 43092
Step 85: 43092 + 513 = 43605
Step 86: 43605 + 513 = 44118
Step 87: 44118 + 513 = 44631
Step 88: 44631 + 513 = 45144
Step 89: 45144 + 513 = 45657
Step 90: 45657 + 513 = 46170
Step 91: 46170 + 513 = 46683
Step 92: 46683 + 513 = 47196
Step 93: 47196 + 513 = 47709
Step 94: 47709 + 513 = 48222
Step 95: 48222 + 513 = 48735
Step 96: 48735 + 513 = 49248
Step 97: 49248 + 513 = 49761
Step 98: 49761 + 513 = 50274
Step 99: 50274 + 513 = 50787
Step 100: 50787 + 513 = 51300
Step 101: 51300 + 513 = 51813
Step 102: 51813 + 513 = 52326
Step 103: 52326 + 513 = 52839
Step 104: 52839 + 513 = 53352
Step 105: 53352 + 513 = 53865
Step 106: 53865 + 513 = 54378
Step 107: 54378 + 513 = 54891
Step 108: 54891 + 513 = 55404
Step 109: 55404 + 513 = 55917
Step 110: 55917 + 513 = 56430
Step 111: 56430 + 513 = 56943
Step 112: 56943 + 513 = 57456
Step 113: 57456 + 513 = 57969
Step 114: 57969 + 513 = 58482
Step 115: 58482 + 513 = 58995
Step 116: 58995 + 513 = 59508
Step 117: 59508 + 513 = 60021
Step 118: 60021 + 513 = 60534
Step 119: 60534 + 513 = 61047
Step 120: 61047 + 513 = 61560
Step 121: 61560 + 513 = 62073
Step 122: 62073 + 513 = 62586
Step 123: 62586 + 513 = 63099
Step 124: 63099 + 513 = 63612
Step 125: 63612 + 513 = 64125
Step 126: 64125 + 513 = 64638
Step 127: 64638 + 513 = 65151
Step 128: 65151 + 513 = 65664
Step 129: 65664 + 513 = 66177
Step 130: 66177 + 513 = 66690
Step 131: 66690 + 513 = 67203
Step 132: 67203 + 513 = 67716
Step 133: 67716 + 513 = 68229
Step 134: 68229 + 513 = 68742
Step 135: 68742 + 513 = 69255
Step 136: 69255 + 513 = 69768
Step 137: 69768 + 513 = 70281
Step 138: 70281 + 513 = 70794
Step 139: 70794 + 513 = 71307
Step 140: 71307 + 513 = 71820
Step 141: 71820 + 513 = 72333
Step 142: 72333 + 513 = 72846
Step 143: 72846 + 513 = 73359
Step 144: 73359 + 513 = 73872
Step 145: 73872 + 513 = 74385
Step 146: 74385 + 513 = 74898
Step 147: 74898 + 513 = 75411
Step 148: 75411 + 513 = 75924
Step 149: 75924 + 513 = 76437
Step 150: 76437 + 513 = 76950
Step 151: 76950 + 513 = 77463
Step 152: 77463 + 513 = 77976
Step 153: 77976 + 513 = 78489
Step 154: 78489 + 513 = 79002
Step 155: 79002 + 513 = 79515
Step 156: 79515 + 513 = 80028
Step 157: 80028 + 513 = 80541
Step 158: 80541 + 513 = 81054

So, 513*158 = 81054