OK, let's work through this together. We're starting with 517 and we're going to multiply it by 80, which means we add 517 to itself 80 times.
Step 1: 0 + 517 = 517
Step 2: 517 + 517 = 1034
Step 3: 1034 + 517 = 1551
Step 4: 1551 + 517 = 2068
Step 5: 2068 + 517 = 2585
Step 6: 2585 + 517 = 3102
Step 7: 3102 + 517 = 3619
Step 8: 3619 + 517 = 4136
Step 9: 4136 + 517 = 4653
Step 10: 4653 + 517 = 5170
Step 11: 5170 + 517 = 5687
Step 12: 5687 + 517 = 6204
Step 13: 6204 + 517 = 6721
Step 14: 6721 + 517 = 7238
Step 15: 7238 + 517 = 7755
Step 16: 7755 + 517 = 8272
Step 17: 8272 + 517 = 8789
Step 18: 8789 + 517 = 9306
Step 19: 9306 + 517 = 9823
Step 20: 9823 + 517 = 10340
Step 21: 10340 + 517 = 10857
Step 22: 10857 + 517 = 11374
Step 23: 11374 + 517 = 11891
Step 24: 11891 + 517 = 12408
Step 25: 12408 + 517 = 12925
Step 26: 12925 + 517 = 13442
Step 27: 13442 + 517 = 13959
Step 28: 13959 + 517 = 14476
Step 29: 14476 + 517 = 14993
Step 30: 14993 + 517 = 15510
Step 31: 15510 + 517 = 16027
Step 32: 16027 + 517 = 16544
Step 33: 16544 + 517 = 17061
Step 34: 17061 + 517 = 17578
Step 35: 17578 + 517 = 18095
Step 36: 18095 + 517 = 18612
Step 37: 18612 + 517 = 19129
Step 38: 19129 + 517 = 19646
Step 39: 19646 + 517 = 20163
Step 40: 20163 + 517 = 20680
Step 41: 20680 + 517 = 21197
Step 42: 21197 + 517 = 21714
Step 43: 21714 + 517 = 22231
Step 44: 22231 + 517 = 22748
Step 45: 22748 + 517 = 23265
Step 46: 23265 + 517 = 23782
Step 47: 23782 + 517 = 24299
Step 48: 24299 + 517 = 24816
Step 49: 24816 + 517 = 25333
Step 50: 25333 + 517 = 25850
Step 51: 25850 + 517 = 26367
Step 52: 26367 + 517 = 26884
Step 53: 26884 + 517 = 27401
Step 54: 27401 + 517 = 27918
Step 55: 27918 + 517 = 28435
Step 56: 28435 + 517 = 28952
Step 57: 28952 + 517 = 29469
Step 58: 29469 + 517 = 29986
Step 59: 29986 + 517 = 30503
Step 60: 30503 + 517 = 31020
Step 61: 31020 + 517 = 31537
Step 62: 31537 + 517 = 32054
Step 63: 32054 + 517 = 32571
Step 64: 32571 + 517 = 33088
Step 65: 33088 + 517 = 33605
Step 66: 33605 + 517 = 34122
Step 67: 34122 + 517 = 34639
Step 68: 34639 + 517 = 35156
Step 69: 35156 + 517 = 35673
Step 70: 35673 + 517 = 36190
Step 71: 36190 + 517 = 36707
Step 72: 36707 + 517 = 37224
Step 73: 37224 + 517 = 37741
Step 74: 37741 + 517 = 38258
Step 75: 38258 + 517 = 38775
Step 76: 38775 + 517 = 39292
Step 77: 39292 + 517 = 39809
Step 78: 39809 + 517 = 40326
Step 79: 40326 + 517 = 40843
Step 80: 40843 + 517 = 41360

So, 517*80 = 41360