Let's roll up our sleeves and solve this. We have 521 and we're going to multiply it by 308, essentially adding 521 to itself 308 times.
Step 1: 0 + 521 = 521
Step 2: 521 + 521 = 1042
Step 3: 1042 + 521 = 1563
Step 4: 1563 + 521 = 2084
Step 5: 2084 + 521 = 2605
Step 6: 2605 + 521 = 3126
Step 7: 3126 + 521 = 3647
Step 8: 3647 + 521 = 4168
Step 9: 4168 + 521 = 4689
Step 10: 4689 + 521 = 5210
Step 11: 5210 + 521 = 5731
Step 12: 5731 + 521 = 6252
Step 13: 6252 + 521 = 6773
Step 14: 6773 + 521 = 7294
Step 15: 7294 + 521 = 7815
Step 16: 7815 + 521 = 8336
Step 17: 8336 + 521 = 8857
Step 18: 8857 + 521 = 9378
Step 19: 9378 + 521 = 9899
Step 20: 9899 + 521 = 10420
Step 21: 10420 + 521 = 10941
Step 22: 10941 + 521 = 11462
Step 23: 11462 + 521 = 11983
Step 24: 11983 + 521 = 12504
Step 25: 12504 + 521 = 13025
Step 26: 13025 + 521 = 13546
Step 27: 13546 + 521 = 14067
Step 28: 14067 + 521 = 14588
Step 29: 14588 + 521 = 15109
Step 30: 15109 + 521 = 15630
Step 31: 15630 + 521 = 16151
Step 32: 16151 + 521 = 16672
Step 33: 16672 + 521 = 17193
Step 34: 17193 + 521 = 17714
Step 35: 17714 + 521 = 18235
Step 36: 18235 + 521 = 18756
Step 37: 18756 + 521 = 19277
Step 38: 19277 + 521 = 19798
Step 39: 19798 + 521 = 20319
Step 40: 20319 + 521 = 20840
Step 41: 20840 + 521 = 21361
Step 42: 21361 + 521 = 21882
Step 43: 21882 + 521 = 22403
Step 44: 22403 + 521 = 22924
Step 45: 22924 + 521 = 23445
Step 46: 23445 + 521 = 23966
Step 47: 23966 + 521 = 24487
Step 48: 24487 + 521 = 25008
Step 49: 25008 + 521 = 25529
Step 50: 25529 + 521 = 26050
Step 51: 26050 + 521 = 26571
Step 52: 26571 + 521 = 27092
Step 53: 27092 + 521 = 27613
Step 54: 27613 + 521 = 28134
Step 55: 28134 + 521 = 28655
Step 56: 28655 + 521 = 29176
Step 57: 29176 + 521 = 29697
Step 58: 29697 + 521 = 30218
Step 59: 30218 + 521 = 30739
Step 60: 30739 + 521 = 31260
Step 61: 31260 + 521 = 31781
Step 62: 31781 + 521 = 32302
Step 63: 32302 + 521 = 32823
Step 64: 32823 + 521 = 33344
Step 65: 33344 + 521 = 33865
Step 66: 33865 + 521 = 34386
Step 67: 34386 + 521 = 34907
Step 68: 34907 + 521 = 35428
Step 69: 35428 + 521 = 35949
Step 70: 35949 + 521 = 36470
Step 71: 36470 + 521 = 36991
Step 72: 36991 + 521 = 37512
Step 73: 37512 + 521 = 38033
Step 74: 38033 + 521 = 38554
Step 75: 38554 + 521 = 39075
Step 76: 39075 + 521 = 39596
Step 77: 39596 + 521 = 40117
Step 78: 40117 + 521 = 40638
Step 79: 40638 + 521 = 41159
Step 80: 41159 + 521 = 41680
Step 81: 41680 + 521 = 42201
Step 82: 42201 + 521 = 42722
Step 83: 42722 + 521 = 43243
Step 84: 43243 + 521 = 43764
Step 85: 43764 + 521 = 44285
Step 86: 44285 + 521 = 44806
Step 87: 44806 + 521 = 45327
Step 88: 45327 + 521 = 45848
Step 89: 45848 + 521 = 46369
Step 90: 46369 + 521 = 46890
Step 91: 46890 + 521 = 47411
Step 92: 47411 + 521 = 47932
Step 93: 47932 + 521 = 48453
Step 94: 48453 + 521 = 48974
Step 95: 48974 + 521 = 49495
Step 96: 49495 + 521 = 50016
Step 97: 50016 + 521 = 50537
Step 98: 50537 + 521 = 51058
Step 99: 51058 + 521 = 51579
Step 100: 51579 + 521 = 52100
Step 101: 52100 + 521 = 52621
Step 102: 52621 + 521 = 53142
Step 103: 53142 + 521 = 53663
Step 104: 53663 + 521 = 54184
Step 105: 54184 + 521 = 54705
Step 106: 54705 + 521 = 55226
Step 107: 55226 + 521 = 55747
Step 108: 55747 + 521 = 56268
Step 109: 56268 + 521 = 56789
Step 110: 56789 + 521 = 57310
Step 111: 57310 + 521 = 57831
Step 112: 57831 + 521 = 58352
Step 113: 58352 + 521 = 58873
Step 114: 58873 + 521 = 59394
Step 115: 59394 + 521 = 59915
Step 116: 59915 + 521 = 60436
Step 117: 60436 + 521 = 60957
Step 118: 60957 + 521 = 61478
Step 119: 61478 + 521 = 61999
Step 120: 61999 + 521 = 62520
Step 121: 62520 + 521 = 63041
Step 122: 63041 + 521 = 63562
Step 123: 63562 + 521 = 64083
Step 124: 64083 + 521 = 64604
Step 125: 64604 + 521 = 65125
Step 126: 65125 + 521 = 65646
Step 127: 65646 + 521 = 66167
Step 128: 66167 + 521 = 66688
Step 129: 66688 + 521 = 67209
Step 130: 67209 + 521 = 67730
Step 131: 67730 + 521 = 68251
Step 132: 68251 + 521 = 68772
Step 133: 68772 + 521 = 69293
Step 134: 69293 + 521 = 69814
Step 135: 69814 + 521 = 70335
Step 136: 70335 + 521 = 70856
Step 137: 70856 + 521 = 71377
Step 138: 71377 + 521 = 71898
Step 139: 71898 + 521 = 72419
Step 140: 72419 + 521 = 72940
Step 141: 72940 + 521 = 73461
Step 142: 73461 + 521 = 73982
Step 143: 73982 + 521 = 74503
Step 144: 74503 + 521 = 75024
Step 145: 75024 + 521 = 75545
Step 146: 75545 + 521 = 76066
Step 147: 76066 + 521 = 76587
Step 148: 76587 + 521 = 77108
Step 149: 77108 + 521 = 77629
Step 150: 77629 + 521 = 78150
Step 151: 78150 + 521 = 78671
Step 152: 78671 + 521 = 79192
Step 153: 79192 + 521 = 79713
Step 154: 79713 + 521 = 80234
Step 155: 80234 + 521 = 80755
Step 156: 80755 + 521 = 81276
Step 157: 81276 + 521 = 81797
Step 158: 81797 + 521 = 82318
Step 159: 82318 + 521 = 82839
Step 160: 82839 + 521 = 83360
Step 161: 83360 + 521 = 83881
Step 162: 83881 + 521 = 84402
Step 163: 84402 + 521 = 84923
Step 164: 84923 + 521 = 85444
Step 165: 85444 + 521 = 85965
Step 166: 85965 + 521 = 86486
Step 167: 86486 + 521 = 87007
Step 168: 87007 + 521 = 87528
Step 169: 87528 + 521 = 88049
Step 170: 88049 + 521 = 88570
Step 171: 88570 + 521 = 89091
Step 172: 89091 + 521 = 89612
Step 173: 89612 + 521 = 90133
Step 174: 90133 + 521 = 90654
Step 175: 90654 + 521 = 91175
Step 176: 91175 + 521 = 91696
Step 177: 91696 + 521 = 92217
Step 178: 92217 + 521 = 92738
Step 179: 92738 + 521 = 93259
Step 180: 93259 + 521 = 93780
Step 181: 93780 + 521 = 94301
Step 182: 94301 + 521 = 94822
Step 183: 94822 + 521 = 95343
Step 184: 95343 + 521 = 95864
Step 185: 95864 + 521 = 96385
Step 186: 96385 + 521 = 96906
Step 187: 96906 + 521 = 97427
Step 188: 97427 + 521 = 97948
Step 189: 97948 + 521 = 98469
Step 190: 98469 + 521 = 98990
Step 191: 98990 + 521 = 99511
Step 192: 99511 + 521 = 100032
Step 193: 100032 + 521 = 100553
Step 194: 100553 + 521 = 101074
Step 195: 101074 + 521 = 101595
Step 196: 101595 + 521 = 102116
Step 197: 102116 + 521 = 102637
Step 198: 102637 + 521 = 103158
Step 199: 103158 + 521 = 103679
Step 200: 103679 + 521 = 104200
Step 201: 104200 + 521 = 104721
Step 202: 104721 + 521 = 105242
Step 203: 105242 + 521 = 105763
Step 204: 105763 + 521 = 106284
Step 205: 106284 + 521 = 106805
Step 206: 106805 + 521 = 107326
Step 207: 107326 + 521 = 107847
Step 208: 107847 + 521 = 108368
Step 209: 108368 + 521 = 108889
Step 210: 108889 + 521 = 109410
Step 211: 109410 + 521 = 109931
Step 212: 109931 + 521 = 110452
Step 213: 110452 + 521 = 110973
Step 214: 110973 + 521 = 111494
Step 215: 111494 + 521 = 112015
Step 216: 112015 + 521 = 112536
Step 217: 112536 + 521 = 113057
Step 218: 113057 + 521 = 113578
Step 219: 113578 + 521 = 114099
Step 220: 114099 + 521 = 114620
Step 221: 114620 + 521 = 115141
Step 222: 115141 + 521 = 115662
Step 223: 115662 + 521 = 116183
Step 224: 116183 + 521 = 116704
Step 225: 116704 + 521 = 117225
Step 226: 117225 + 521 = 117746
Step 227: 117746 + 521 = 118267
Step 228: 118267 + 521 = 118788
Step 229: 118788 + 521 = 119309
Step 230: 119309 + 521 = 119830
Step 231: 119830 + 521 = 120351
Step 232: 120351 + 521 = 120872
Step 233: 120872 + 521 = 121393
Step 234: 121393 + 521 = 121914
Step 235: 121914 + 521 = 122435
Step 236: 122435 + 521 = 122956
Step 237: 122956 + 521 = 123477
Step 238: 123477 + 521 = 123998
Step 239: 123998 + 521 = 124519
Step 240: 124519 + 521 = 125040
Step 241: 125040 + 521 = 125561
Step 242: 125561 + 521 = 126082
Step 243: 126082 + 521 = 126603
Step 244: 126603 + 521 = 127124
Step 245: 127124 + 521 = 127645
Step 246: 127645 + 521 = 128166
Step 247: 128166 + 521 = 128687
Step 248: 128687 + 521 = 129208
Step 249: 129208 + 521 = 129729
Step 250: 129729 + 521 = 130250
Step 251: 130250 + 521 = 130771
Step 252: 130771 + 521 = 131292
Step 253: 131292 + 521 = 131813
Step 254: 131813 + 521 = 132334
Step 255: 132334 + 521 = 132855
Step 256: 132855 + 521 = 133376
Step 257: 133376 + 521 = 133897
Step 258: 133897 + 521 = 134418
Step 259: 134418 + 521 = 134939
Step 260: 134939 + 521 = 135460
Step 261: 135460 + 521 = 135981
Step 262: 135981 + 521 = 136502
Step 263: 136502 + 521 = 137023
Step 264: 137023 + 521 = 137544
Step 265: 137544 + 521 = 138065
Step 266: 138065 + 521 = 138586
Step 267: 138586 + 521 = 139107
Step 268: 139107 + 521 = 139628
Step 269: 139628 + 521 = 140149
Step 270: 140149 + 521 = 140670
Step 271: 140670 + 521 = 141191
Step 272: 141191 + 521 = 141712
Step 273: 141712 + 521 = 142233
Step 274: 142233 + 521 = 142754
Step 275: 142754 + 521 = 143275
Step 276: 143275 + 521 = 143796
Step 277: 143796 + 521 = 144317
Step 278: 144317 + 521 = 144838
Step 279: 144838 + 521 = 145359
Step 280: 145359 + 521 = 145880
Step 281: 145880 + 521 = 146401
Step 282: 146401 + 521 = 146922
Step 283: 146922 + 521 = 147443
Step 284: 147443 + 521 = 147964
Step 285: 147964 + 521 = 148485
Step 286: 148485 + 521 = 149006
Step 287: 149006 + 521 = 149527
Step 288: 149527 + 521 = 150048
Step 289: 150048 + 521 = 150569
Step 290: 150569 + 521 = 151090
Step 291: 151090 + 521 = 151611
Step 292: 151611 + 521 = 152132
Step 293: 152132 + 521 = 152653
Step 294: 152653 + 521 = 153174
Step 295: 153174 + 521 = 153695
Step 296: 153695 + 521 = 154216
Step 297: 154216 + 521 = 154737
Step 298: 154737 + 521 = 155258
Step 299: 155258 + 521 = 155779
Step 300: 155779 + 521 = 156300
Step 301: 156300 + 521 = 156821
Step 302: 156821 + 521 = 157342
Step 303: 157342 + 521 = 157863
Step 304: 157863 + 521 = 158384
Step 305: 158384 + 521 = 158905
Step 306: 158905 + 521 = 159426
Step 307: 159426 + 521 = 159947
Step 308: 159947 + 521 = 160468

So, 521*308 = 160468