Let's roll up our sleeves and solve this. We have 142 and we're going to multiply it by 57, essentially adding 142 to itself 57 times.
Step 1: 0 + 142 = 142
Step 2: 142 + 142 = 284
Step 3: 284 + 142 = 426
Step 4: 426 + 142 = 568
Step 5: 568 + 142 = 710
Step 6: 710 + 142 = 852
Step 7: 852 + 142 = 994
Step 8: 994 + 142 = 1136
Step 9: 1136 + 142 = 1278
Step 10: 1278 + 142 = 1420
Step 11: 1420 + 142 = 1562
Step 12: 1562 + 142 = 1704
Step 13: 1704 + 142 = 1846
Step 14: 1846 + 142 = 1988
Step 15: 1988 + 142 = 2130
Step 16: 2130 + 142 = 2272
Step 17: 2272 + 142 = 2414
Step 18: 2414 + 142 = 2556
Step 19: 2556 + 142 = 2698
Step 20: 2698 + 142 = 2840
Step 21: 2840 + 142 = 2982
Step 22: 2982 + 142 = 3124
Step 23: 3124 + 142 = 3266
Step 24: 3266 + 142 = 3408
Step 25: 3408 + 142 = 3550
Step 26: 3550 + 142 = 3692
Step 27: 3692 + 142 = 3834
Step 28: 3834 + 142 = 3976
Step 29: 3976 + 142 = 4118
Step 30: 4118 + 142 = 4260
Step 31: 4260 + 142 = 4402
Step 32: 4402 + 142 = 4544
Step 33: 4544 + 142 = 4686
Step 34: 4686 + 142 = 4828
Step 35: 4828 + 142 = 4970
Step 36: 4970 + 142 = 5112
Step 37: 5112 + 142 = 5254
Step 38: 5254 + 142 = 5396
Step 39: 5396 + 142 = 5538
Step 40: 5538 + 142 = 5680
Step 41: 5680 + 142 = 5822
Step 42: 5822 + 142 = 5964
Step 43: 5964 + 142 = 6106
Step 44: 6106 + 142 = 6248
Step 45: 6248 + 142 = 6390
Step 46: 6390 + 142 = 6532
Step 47: 6532 + 142 = 6674
Step 48: 6674 + 142 = 6816
Step 49: 6816 + 142 = 6958
Step 50: 6958 + 142 = 7100
Step 51: 7100 + 142 = 7242
Step 52: 7242 + 142 = 7384
Step 53: 7384 + 142 = 7526
Step 54: 7526 + 142 = 7668
Step 55: 7668 + 142 = 7810
Step 56: 7810 + 142 = 7952
Step 57: 7952 + 142 = 8094

So, 142*57 = 8094