Alright, let's solve this math problem step by step. First, we have the number 357. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 143. So, we're going to take the number 357 and add it to itself 143 times.
Step 1: 0 + 357 = 357
Step 2: 357 + 357 = 714
Step 3: 714 + 357 = 1071
Step 4: 1071 + 357 = 1428
Step 5: 1428 + 357 = 1785
Step 6: 1785 + 357 = 2142
Step 7: 2142 + 357 = 2499
Step 8: 2499 + 357 = 2856
Step 9: 2856 + 357 = 3213
Step 10: 3213 + 357 = 3570
Step 11: 3570 + 357 = 3927
Step 12: 3927 + 357 = 4284
Step 13: 4284 + 357 = 4641
Step 14: 4641 + 357 = 4998
Step 15: 4998 + 357 = 5355
Step 16: 5355 + 357 = 5712
Step 17: 5712 + 357 = 6069
Step 18: 6069 + 357 = 6426
Step 19: 6426 + 357 = 6783
Step 20: 6783 + 357 = 7140
Step 21: 7140 + 357 = 7497
Step 22: 7497 + 357 = 7854
Step 23: 7854 + 357 = 8211
Step 24: 8211 + 357 = 8568
Step 25: 8568 + 357 = 8925
Step 26: 8925 + 357 = 9282
Step 27: 9282 + 357 = 9639
Step 28: 9639 + 357 = 9996
Step 29: 9996 + 357 = 10353
Step 30: 10353 + 357 = 10710
Step 31: 10710 + 357 = 11067
Step 32: 11067 + 357 = 11424
Step 33: 11424 + 357 = 11781
Step 34: 11781 + 357 = 12138
Step 35: 12138 + 357 = 12495
Step 36: 12495 + 357 = 12852
Step 37: 12852 + 357 = 13209
Step 38: 13209 + 357 = 13566
Step 39: 13566 + 357 = 13923
Step 40: 13923 + 357 = 14280
Step 41: 14280 + 357 = 14637
Step 42: 14637 + 357 = 14994
Step 43: 14994 + 357 = 15351
Step 44: 15351 + 357 = 15708
Step 45: 15708 + 357 = 16065
Step 46: 16065 + 357 = 16422
Step 47: 16422 + 357 = 16779
Step 48: 16779 + 357 = 17136
Step 49: 17136 + 357 = 17493
Step 50: 17493 + 357 = 17850
Step 51: 17850 + 357 = 18207
Step 52: 18207 + 357 = 18564
Step 53: 18564 + 357 = 18921
Step 54: 18921 + 357 = 19278
Step 55: 19278 + 357 = 19635
Step 56: 19635 + 357 = 19992
Step 57: 19992 + 357 = 20349
Step 58: 20349 + 357 = 20706
Step 59: 20706 + 357 = 21063
Step 60: 21063 + 357 = 21420
Step 61: 21420 + 357 = 21777
Step 62: 21777 + 357 = 22134
Step 63: 22134 + 357 = 22491
Step 64: 22491 + 357 = 22848
Step 65: 22848 + 357 = 23205
Step 66: 23205 + 357 = 23562
Step 67: 23562 + 357 = 23919
Step 68: 23919 + 357 = 24276
Step 69: 24276 + 357 = 24633
Step 70: 24633 + 357 = 24990
Step 71: 24990 + 357 = 25347
Step 72: 25347 + 357 = 25704
Step 73: 25704 + 357 = 26061
Step 74: 26061 + 357 = 26418
Step 75: 26418 + 357 = 26775
Step 76: 26775 + 357 = 27132
Step 77: 27132 + 357 = 27489
Step 78: 27489 + 357 = 27846
Step 79: 27846 + 357 = 28203
Step 80: 28203 + 357 = 28560
Step 81: 28560 + 357 = 28917
Step 82: 28917 + 357 = 29274
Step 83: 29274 + 357 = 29631
Step 84: 29631 + 357 = 29988
Step 85: 29988 + 357 = 30345
Step 86: 30345 + 357 = 30702
Step 87: 30702 + 357 = 31059
Step 88: 31059 + 357 = 31416
Step 89: 31416 + 357 = 31773
Step 90: 31773 + 357 = 32130
Step 91: 32130 + 357 = 32487
Step 92: 32487 + 357 = 32844
Step 93: 32844 + 357 = 33201
Step 94: 33201 + 357 = 33558
Step 95: 33558 + 357 = 33915
Step 96: 33915 + 357 = 34272
Step 97: 34272 + 357 = 34629
Step 98: 34629 + 357 = 34986
Step 99: 34986 + 357 = 35343
Step 100: 35343 + 357 = 35700
Step 101: 35700 + 357 = 36057
Step 102: 36057 + 357 = 36414
Step 103: 36414 + 357 = 36771
Step 104: 36771 + 357 = 37128
Step 105: 37128 + 357 = 37485
Step 106: 37485 + 357 = 37842
Step 107: 37842 + 357 = 38199
Step 108: 38199 + 357 = 38556
Step 109: 38556 + 357 = 38913
Step 110: 38913 + 357 = 39270
Step 111: 39270 + 357 = 39627
Step 112: 39627 + 357 = 39984
Step 113: 39984 + 357 = 40341
Step 114: 40341 + 357 = 40698
Step 115: 40698 + 357 = 41055
Step 116: 41055 + 357 = 41412
Step 117: 41412 + 357 = 41769
Step 118: 41769 + 357 = 42126
Step 119: 42126 + 357 = 42483
Step 120: 42483 + 357 = 42840
Step 121: 42840 + 357 = 43197
Step 122: 43197 + 357 = 43554
Step 123: 43554 + 357 = 43911
Step 124: 43911 + 357 = 44268
Step 125: 44268 + 357 = 44625
Step 126: 44625 + 357 = 44982
Step 127: 44982 + 357 = 45339
Step 128: 45339 + 357 = 45696
Step 129: 45696 + 357 = 46053
Step 130: 46053 + 357 = 46410
Step 131: 46410 + 357 = 46767
Step 132: 46767 + 357 = 47124
Step 133: 47124 + 357 = 47481
Step 134: 47481 + 357 = 47838
Step 135: 47838 + 357 = 48195
Step 136: 48195 + 357 = 48552
Step 137: 48552 + 357 = 48909
Step 138: 48909 + 357 = 49266
Step 139: 49266 + 357 = 49623
Step 140: 49623 + 357 = 49980
Step 141: 49980 + 357 = 50337
Step 142: 50337 + 357 = 50694
Step 143: 50694 + 357 = 51051

So, 357*143 = 51051