OK, let's crack this. We're given 879 and our task is to multiply it by 57. Essentially, we'll be adding 879 to itself 57 times.
Step 1: 0 + 879 = 879
Step 2: 879 + 879 = 1758
Step 3: 1758 + 879 = 2637
Step 4: 2637 + 879 = 3516
Step 5: 3516 + 879 = 4395
Step 6: 4395 + 879 = 5274
Step 7: 5274 + 879 = 6153
Step 8: 6153 + 879 = 7032
Step 9: 7032 + 879 = 7911
Step 10: 7911 + 879 = 8790
Step 11: 8790 + 879 = 9669
Step 12: 9669 + 879 = 10548
Step 13: 10548 + 879 = 11427
Step 14: 11427 + 879 = 12306
Step 15: 12306 + 879 = 13185
Step 16: 13185 + 879 = 14064
Step 17: 14064 + 879 = 14943
Step 18: 14943 + 879 = 15822
Step 19: 15822 + 879 = 16701
Step 20: 16701 + 879 = 17580
Step 21: 17580 + 879 = 18459
Step 22: 18459 + 879 = 19338
Step 23: 19338 + 879 = 20217
Step 24: 20217 + 879 = 21096
Step 25: 21096 + 879 = 21975
Step 26: 21975 + 879 = 22854
Step 27: 22854 + 879 = 23733
Step 28: 23733 + 879 = 24612
Step 29: 24612 + 879 = 25491
Step 30: 25491 + 879 = 26370
Step 31: 26370 + 879 = 27249
Step 32: 27249 + 879 = 28128
Step 33: 28128 + 879 = 29007
Step 34: 29007 + 879 = 29886
Step 35: 29886 + 879 = 30765
Step 36: 30765 + 879 = 31644
Step 37: 31644 + 879 = 32523
Step 38: 32523 + 879 = 33402
Step 39: 33402 + 879 = 34281
Step 40: 34281 + 879 = 35160
Step 41: 35160 + 879 = 36039
Step 42: 36039 + 879 = 36918
Step 43: 36918 + 879 = 37797
Step 44: 37797 + 879 = 38676
Step 45: 38676 + 879 = 39555
Step 46: 39555 + 879 = 40434
Step 47: 40434 + 879 = 41313
Step 48: 41313 + 879 = 42192
Step 49: 42192 + 879 = 43071
Step 50: 43071 + 879 = 43950
Step 51: 43950 + 879 = 44829
Step 52: 44829 + 879 = 45708
Step 53: 45708 + 879 = 46587
Step 54: 46587 + 879 = 47466
Step 55: 47466 + 879 = 48345
Step 56: 48345 + 879 = 49224
Step 57: 49224 + 879 = 50103

So, 879*57 = 50103