OK, let's work through this together. We're starting with 372 and we're going to multiply it by 91, which means we add 372 to itself 91 times.
Step 1: 0 + 372 = 372
Step 2: 372 + 372 = 744
Step 3: 744 + 372 = 1116
Step 4: 1116 + 372 = 1488
Step 5: 1488 + 372 = 1860
Step 6: 1860 + 372 = 2232
Step 7: 2232 + 372 = 2604
Step 8: 2604 + 372 = 2976
Step 9: 2976 + 372 = 3348
Step 10: 3348 + 372 = 3720
Step 11: 3720 + 372 = 4092
Step 12: 4092 + 372 = 4464
Step 13: 4464 + 372 = 4836
Step 14: 4836 + 372 = 5208
Step 15: 5208 + 372 = 5580
Step 16: 5580 + 372 = 5952
Step 17: 5952 + 372 = 6324
Step 18: 6324 + 372 = 6696
Step 19: 6696 + 372 = 7068
Step 20: 7068 + 372 = 7440
Step 21: 7440 + 372 = 7812
Step 22: 7812 + 372 = 8184
Step 23: 8184 + 372 = 8556
Step 24: 8556 + 372 = 8928
Step 25: 8928 + 372 = 9300
Step 26: 9300 + 372 = 9672
Step 27: 9672 + 372 = 10044
Step 28: 10044 + 372 = 10416
Step 29: 10416 + 372 = 10788
Step 30: 10788 + 372 = 11160
Step 31: 11160 + 372 = 11532
Step 32: 11532 + 372 = 11904
Step 33: 11904 + 372 = 12276
Step 34: 12276 + 372 = 12648
Step 35: 12648 + 372 = 13020
Step 36: 13020 + 372 = 13392
Step 37: 13392 + 372 = 13764
Step 38: 13764 + 372 = 14136
Step 39: 14136 + 372 = 14508
Step 40: 14508 + 372 = 14880
Step 41: 14880 + 372 = 15252
Step 42: 15252 + 372 = 15624
Step 43: 15624 + 372 = 15996
Step 44: 15996 + 372 = 16368
Step 45: 16368 + 372 = 16740
Step 46: 16740 + 372 = 17112
Step 47: 17112 + 372 = 17484
Step 48: 17484 + 372 = 17856
Step 49: 17856 + 372 = 18228
Step 50: 18228 + 372 = 18600
Step 51: 18600 + 372 = 18972
Step 52: 18972 + 372 = 19344
Step 53: 19344 + 372 = 19716
Step 54: 19716 + 372 = 20088
Step 55: 20088 + 372 = 20460
Step 56: 20460 + 372 = 20832
Step 57: 20832 + 372 = 21204
Step 58: 21204 + 372 = 21576
Step 59: 21576 + 372 = 21948
Step 60: 21948 + 372 = 22320
Step 61: 22320 + 372 = 22692
Step 62: 22692 + 372 = 23064
Step 63: 23064 + 372 = 23436
Step 64: 23436 + 372 = 23808
Step 65: 23808 + 372 = 24180
Step 66: 24180 + 372 = 24552
Step 67: 24552 + 372 = 24924
Step 68: 24924 + 372 = 25296
Step 69: 25296 + 372 = 25668
Step 70: 25668 + 372 = 26040
Step 71: 26040 + 372 = 26412
Step 72: 26412 + 372 = 26784
Step 73: 26784 + 372 = 27156
Step 74: 27156 + 372 = 27528
Step 75: 27528 + 372 = 27900
Step 76: 27900 + 372 = 28272
Step 77: 28272 + 372 = 28644
Step 78: 28644 + 372 = 29016
Step 79: 29016 + 372 = 29388
Step 80: 29388 + 372 = 29760
Step 81: 29760 + 372 = 30132
Step 82: 30132 + 372 = 30504
Step 83: 30504 + 372 = 30876
Step 84: 30876 + 372 = 31248
Step 85: 31248 + 372 = 31620
Step 86: 31620 + 372 = 31992
Step 87: 31992 + 372 = 32364
Step 88: 32364 + 372 = 32736
Step 89: 32736 + 372 = 33108
Step 90: 33108 + 372 = 33480
Step 91: 33480 + 372 = 33852

So, 372*91 = 33852