OK, let's crack this. We're given 379 and our task is to multiply it by 42. Essentially, we'll be adding 379 to itself 42 times.
Step 1: 0 + 379 = 379
Step 2: 379 + 379 = 758
Step 3: 758 + 379 = 1137
Step 4: 1137 + 379 = 1516
Step 5: 1516 + 379 = 1895
Step 6: 1895 + 379 = 2274
Step 7: 2274 + 379 = 2653
Step 8: 2653 + 379 = 3032
Step 9: 3032 + 379 = 3411
Step 10: 3411 + 379 = 3790
Step 11: 3790 + 379 = 4169
Step 12: 4169 + 379 = 4548
Step 13: 4548 + 379 = 4927
Step 14: 4927 + 379 = 5306
Step 15: 5306 + 379 = 5685
Step 16: 5685 + 379 = 6064
Step 17: 6064 + 379 = 6443
Step 18: 6443 + 379 = 6822
Step 19: 6822 + 379 = 7201
Step 20: 7201 + 379 = 7580
Step 21: 7580 + 379 = 7959
Step 22: 7959 + 379 = 8338
Step 23: 8338 + 379 = 8717
Step 24: 8717 + 379 = 9096
Step 25: 9096 + 379 = 9475
Step 26: 9475 + 379 = 9854
Step 27: 9854 + 379 = 10233
Step 28: 10233 + 379 = 10612
Step 29: 10612 + 379 = 10991
Step 30: 10991 + 379 = 11370
Step 31: 11370 + 379 = 11749
Step 32: 11749 + 379 = 12128
Step 33: 12128 + 379 = 12507
Step 34: 12507 + 379 = 12886
Step 35: 12886 + 379 = 13265
Step 36: 13265 + 379 = 13644
Step 37: 13644 + 379 = 14023
Step 38: 14023 + 379 = 14402
Step 39: 14402 + 379 = 14781
Step 40: 14781 + 379 = 15160
Step 41: 15160 + 379 = 15539
Step 42: 15539 + 379 = 15918

So, 379*42 = 15918