Alright, let's solve this math problem step by step. First, we have the number 641. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 80. So, we're going to take the number 641 and add it to itself 80 times.
Step 1: 0 + 641 = 641
Step 2: 641 + 641 = 1282
Step 3: 1282 + 641 = 1923
Step 4: 1923 + 641 = 2564
Step 5: 2564 + 641 = 3205
Step 6: 3205 + 641 = 3846
Step 7: 3846 + 641 = 4487
Step 8: 4487 + 641 = 5128
Step 9: 5128 + 641 = 5769
Step 10: 5769 + 641 = 6410
Step 11: 6410 + 641 = 7051
Step 12: 7051 + 641 = 7692
Step 13: 7692 + 641 = 8333
Step 14: 8333 + 641 = 8974
Step 15: 8974 + 641 = 9615
Step 16: 9615 + 641 = 10256
Step 17: 10256 + 641 = 10897
Step 18: 10897 + 641 = 11538
Step 19: 11538 + 641 = 12179
Step 20: 12179 + 641 = 12820
Step 21: 12820 + 641 = 13461
Step 22: 13461 + 641 = 14102
Step 23: 14102 + 641 = 14743
Step 24: 14743 + 641 = 15384
Step 25: 15384 + 641 = 16025
Step 26: 16025 + 641 = 16666
Step 27: 16666 + 641 = 17307
Step 28: 17307 + 641 = 17948
Step 29: 17948 + 641 = 18589
Step 30: 18589 + 641 = 19230
Step 31: 19230 + 641 = 19871
Step 32: 19871 + 641 = 20512
Step 33: 20512 + 641 = 21153
Step 34: 21153 + 641 = 21794
Step 35: 21794 + 641 = 22435
Step 36: 22435 + 641 = 23076
Step 37: 23076 + 641 = 23717
Step 38: 23717 + 641 = 24358
Step 39: 24358 + 641 = 24999
Step 40: 24999 + 641 = 25640
Step 41: 25640 + 641 = 26281
Step 42: 26281 + 641 = 26922
Step 43: 26922 + 641 = 27563
Step 44: 27563 + 641 = 28204
Step 45: 28204 + 641 = 28845
Step 46: 28845 + 641 = 29486
Step 47: 29486 + 641 = 30127
Step 48: 30127 + 641 = 30768
Step 49: 30768 + 641 = 31409
Step 50: 31409 + 641 = 32050
Step 51: 32050 + 641 = 32691
Step 52: 32691 + 641 = 33332
Step 53: 33332 + 641 = 33973
Step 54: 33973 + 641 = 34614
Step 55: 34614 + 641 = 35255
Step 56: 35255 + 641 = 35896
Step 57: 35896 + 641 = 36537
Step 58: 36537 + 641 = 37178
Step 59: 37178 + 641 = 37819
Step 60: 37819 + 641 = 38460
Step 61: 38460 + 641 = 39101
Step 62: 39101 + 641 = 39742
Step 63: 39742 + 641 = 40383
Step 64: 40383 + 641 = 41024
Step 65: 41024 + 641 = 41665
Step 66: 41665 + 641 = 42306
Step 67: 42306 + 641 = 42947
Step 68: 42947 + 641 = 43588
Step 69: 43588 + 641 = 44229
Step 70: 44229 + 641 = 44870
Step 71: 44870 + 641 = 45511
Step 72: 45511 + 641 = 46152
Step 73: 46152 + 641 = 46793
Step 74: 46793 + 641 = 47434
Step 75: 47434 + 641 = 48075
Step 76: 48075 + 641 = 48716
Step 77: 48716 + 641 = 49357
Step 78: 49357 + 641 = 49998
Step 79: 49998 + 641 = 50639
Step 80: 50639 + 641 = 51280

So, 641*80 = 51280