OK, let's work through this together. We're starting with 370 and we're going to multiply it by 42, which means we add 370 to itself 42 times.
Step 1: 0 + 370 = 370
Step 2: 370 + 370 = 740
Step 3: 740 + 370 = 1110
Step 4: 1110 + 370 = 1480
Step 5: 1480 + 370 = 1850
Step 6: 1850 + 370 = 2220
Step 7: 2220 + 370 = 2590
Step 8: 2590 + 370 = 2960
Step 9: 2960 + 370 = 3330
Step 10: 3330 + 370 = 3700
Step 11: 3700 + 370 = 4070
Step 12: 4070 + 370 = 4440
Step 13: 4440 + 370 = 4810
Step 14: 4810 + 370 = 5180
Step 15: 5180 + 370 = 5550
Step 16: 5550 + 370 = 5920
Step 17: 5920 + 370 = 6290
Step 18: 6290 + 370 = 6660
Step 19: 6660 + 370 = 7030
Step 20: 7030 + 370 = 7400
Step 21: 7400 + 370 = 7770
Step 22: 7770 + 370 = 8140
Step 23: 8140 + 370 = 8510
Step 24: 8510 + 370 = 8880
Step 25: 8880 + 370 = 9250
Step 26: 9250 + 370 = 9620
Step 27: 9620 + 370 = 9990
Step 28: 9990 + 370 = 10360
Step 29: 10360 + 370 = 10730
Step 30: 10730 + 370 = 11100
Step 31: 11100 + 370 = 11470
Step 32: 11470 + 370 = 11840
Step 33: 11840 + 370 = 12210
Step 34: 12210 + 370 = 12580
Step 35: 12580 + 370 = 12950
Step 36: 12950 + 370 = 13320
Step 37: 13320 + 370 = 13690
Step 38: 13690 + 370 = 14060
Step 39: 14060 + 370 = 14430
Step 40: 14430 + 370 = 14800
Step 41: 14800 + 370 = 15170
Step 42: 15170 + 370 = 15540

So, 370*42 = 15540