Sure thing, let's get straight to it. We start with 381 and we're going to multiply it by 99, which means adding 381 to itself 99 times.
Step 1: 0 + 381 = 381
Step 2: 381 + 381 = 762
Step 3: 762 + 381 = 1143
Step 4: 1143 + 381 = 1524
Step 5: 1524 + 381 = 1905
Step 6: 1905 + 381 = 2286
Step 7: 2286 + 381 = 2667
Step 8: 2667 + 381 = 3048
Step 9: 3048 + 381 = 3429
Step 10: 3429 + 381 = 3810
Step 11: 3810 + 381 = 4191
Step 12: 4191 + 381 = 4572
Step 13: 4572 + 381 = 4953
Step 14: 4953 + 381 = 5334
Step 15: 5334 + 381 = 5715
Step 16: 5715 + 381 = 6096
Step 17: 6096 + 381 = 6477
Step 18: 6477 + 381 = 6858
Step 19: 6858 + 381 = 7239
Step 20: 7239 + 381 = 7620
Step 21: 7620 + 381 = 8001
Step 22: 8001 + 381 = 8382
Step 23: 8382 + 381 = 8763
Step 24: 8763 + 381 = 9144
Step 25: 9144 + 381 = 9525
Step 26: 9525 + 381 = 9906
Step 27: 9906 + 381 = 10287
Step 28: 10287 + 381 = 10668
Step 29: 10668 + 381 = 11049
Step 30: 11049 + 381 = 11430
Step 31: 11430 + 381 = 11811
Step 32: 11811 + 381 = 12192
Step 33: 12192 + 381 = 12573
Step 34: 12573 + 381 = 12954
Step 35: 12954 + 381 = 13335
Step 36: 13335 + 381 = 13716
Step 37: 13716 + 381 = 14097
Step 38: 14097 + 381 = 14478
Step 39: 14478 + 381 = 14859
Step 40: 14859 + 381 = 15240
Step 41: 15240 + 381 = 15621
Step 42: 15621 + 381 = 16002
Step 43: 16002 + 381 = 16383
Step 44: 16383 + 381 = 16764
Step 45: 16764 + 381 = 17145
Step 46: 17145 + 381 = 17526
Step 47: 17526 + 381 = 17907
Step 48: 17907 + 381 = 18288
Step 49: 18288 + 381 = 18669
Step 50: 18669 + 381 = 19050
Step 51: 19050 + 381 = 19431
Step 52: 19431 + 381 = 19812
Step 53: 19812 + 381 = 20193
Step 54: 20193 + 381 = 20574
Step 55: 20574 + 381 = 20955
Step 56: 20955 + 381 = 21336
Step 57: 21336 + 381 = 21717
Step 58: 21717 + 381 = 22098
Step 59: 22098 + 381 = 22479
Step 60: 22479 + 381 = 22860
Step 61: 22860 + 381 = 23241
Step 62: 23241 + 381 = 23622
Step 63: 23622 + 381 = 24003
Step 64: 24003 + 381 = 24384
Step 65: 24384 + 381 = 24765
Step 66: 24765 + 381 = 25146
Step 67: 25146 + 381 = 25527
Step 68: 25527 + 381 = 25908
Step 69: 25908 + 381 = 26289
Step 70: 26289 + 381 = 26670
Step 71: 26670 + 381 = 27051
Step 72: 27051 + 381 = 27432
Step 73: 27432 + 381 = 27813
Step 74: 27813 + 381 = 28194
Step 75: 28194 + 381 = 28575
Step 76: 28575 + 381 = 28956
Step 77: 28956 + 381 = 29337
Step 78: 29337 + 381 = 29718
Step 79: 29718 + 381 = 30099
Step 80: 30099 + 381 = 30480
Step 81: 30480 + 381 = 30861
Step 82: 30861 + 381 = 31242
Step 83: 31242 + 381 = 31623
Step 84: 31623 + 381 = 32004
Step 85: 32004 + 381 = 32385
Step 86: 32385 + 381 = 32766
Step 87: 32766 + 381 = 33147
Step 88: 33147 + 381 = 33528
Step 89: 33528 + 381 = 33909
Step 90: 33909 + 381 = 34290
Step 91: 34290 + 381 = 34671
Step 92: 34671 + 381 = 35052
Step 93: 35052 + 381 = 35433
Step 94: 35433 + 381 = 35814
Step 95: 35814 + 381 = 36195
Step 96: 36195 + 381 = 36576
Step 97: 36576 + 381 = 36957
Step 98: 36957 + 381 = 37338
Step 99: 37338 + 381 = 37719

So, 381*99 = 37719