Let's roll up our sleeves and solve this. We have 903 and we're going to multiply it by 131, essentially adding 903 to itself 131 times.
Step 1: 0 + 903 = 903
Step 2: 903 + 903 = 1806
Step 3: 1806 + 903 = 2709
Step 4: 2709 + 903 = 3612
Step 5: 3612 + 903 = 4515
Step 6: 4515 + 903 = 5418
Step 7: 5418 + 903 = 6321
Step 8: 6321 + 903 = 7224
Step 9: 7224 + 903 = 8127
Step 10: 8127 + 903 = 9030
Step 11: 9030 + 903 = 9933
Step 12: 9933 + 903 = 10836
Step 13: 10836 + 903 = 11739
Step 14: 11739 + 903 = 12642
Step 15: 12642 + 903 = 13545
Step 16: 13545 + 903 = 14448
Step 17: 14448 + 903 = 15351
Step 18: 15351 + 903 = 16254
Step 19: 16254 + 903 = 17157
Step 20: 17157 + 903 = 18060
Step 21: 18060 + 903 = 18963
Step 22: 18963 + 903 = 19866
Step 23: 19866 + 903 = 20769
Step 24: 20769 + 903 = 21672
Step 25: 21672 + 903 = 22575
Step 26: 22575 + 903 = 23478
Step 27: 23478 + 903 = 24381
Step 28: 24381 + 903 = 25284
Step 29: 25284 + 903 = 26187
Step 30: 26187 + 903 = 27090
Step 31: 27090 + 903 = 27993
Step 32: 27993 + 903 = 28896
Step 33: 28896 + 903 = 29799
Step 34: 29799 + 903 = 30702
Step 35: 30702 + 903 = 31605
Step 36: 31605 + 903 = 32508
Step 37: 32508 + 903 = 33411
Step 38: 33411 + 903 = 34314
Step 39: 34314 + 903 = 35217
Step 40: 35217 + 903 = 36120
Step 41: 36120 + 903 = 37023
Step 42: 37023 + 903 = 37926
Step 43: 37926 + 903 = 38829
Step 44: 38829 + 903 = 39732
Step 45: 39732 + 903 = 40635
Step 46: 40635 + 903 = 41538
Step 47: 41538 + 903 = 42441
Step 48: 42441 + 903 = 43344
Step 49: 43344 + 903 = 44247
Step 50: 44247 + 903 = 45150
Step 51: 45150 + 903 = 46053
Step 52: 46053 + 903 = 46956
Step 53: 46956 + 903 = 47859
Step 54: 47859 + 903 = 48762
Step 55: 48762 + 903 = 49665
Step 56: 49665 + 903 = 50568
Step 57: 50568 + 903 = 51471
Step 58: 51471 + 903 = 52374
Step 59: 52374 + 903 = 53277
Step 60: 53277 + 903 = 54180
Step 61: 54180 + 903 = 55083
Step 62: 55083 + 903 = 55986
Step 63: 55986 + 903 = 56889
Step 64: 56889 + 903 = 57792
Step 65: 57792 + 903 = 58695
Step 66: 58695 + 903 = 59598
Step 67: 59598 + 903 = 60501
Step 68: 60501 + 903 = 61404
Step 69: 61404 + 903 = 62307
Step 70: 62307 + 903 = 63210
Step 71: 63210 + 903 = 64113
Step 72: 64113 + 903 = 65016
Step 73: 65016 + 903 = 65919
Step 74: 65919 + 903 = 66822
Step 75: 66822 + 903 = 67725
Step 76: 67725 + 903 = 68628
Step 77: 68628 + 903 = 69531
Step 78: 69531 + 903 = 70434
Step 79: 70434 + 903 = 71337
Step 80: 71337 + 903 = 72240
Step 81: 72240 + 903 = 73143
Step 82: 73143 + 903 = 74046
Step 83: 74046 + 903 = 74949
Step 84: 74949 + 903 = 75852
Step 85: 75852 + 903 = 76755
Step 86: 76755 + 903 = 77658
Step 87: 77658 + 903 = 78561
Step 88: 78561 + 903 = 79464
Step 89: 79464 + 903 = 80367
Step 90: 80367 + 903 = 81270
Step 91: 81270 + 903 = 82173
Step 92: 82173 + 903 = 83076
Step 93: 83076 + 903 = 83979
Step 94: 83979 + 903 = 84882
Step 95: 84882 + 903 = 85785
Step 96: 85785 + 903 = 86688
Step 97: 86688 + 903 = 87591
Step 98: 87591 + 903 = 88494
Step 99: 88494 + 903 = 89397
Step 100: 89397 + 903 = 90300
Step 101: 90300 + 903 = 91203
Step 102: 91203 + 903 = 92106
Step 103: 92106 + 903 = 93009
Step 104: 93009 + 903 = 93912
Step 105: 93912 + 903 = 94815
Step 106: 94815 + 903 = 95718
Step 107: 95718 + 903 = 96621
Step 108: 96621 + 903 = 97524
Step 109: 97524 + 903 = 98427
Step 110: 98427 + 903 = 99330
Step 111: 99330 + 903 = 100233
Step 112: 100233 + 903 = 101136
Step 113: 101136 + 903 = 102039
Step 114: 102039 + 903 = 102942
Step 115: 102942 + 903 = 103845
Step 116: 103845 + 903 = 104748
Step 117: 104748 + 903 = 105651
Step 118: 105651 + 903 = 106554
Step 119: 106554 + 903 = 107457
Step 120: 107457 + 903 = 108360
Step 121: 108360 + 903 = 109263
Step 122: 109263 + 903 = 110166
Step 123: 110166 + 903 = 111069
Step 124: 111069 + 903 = 111972
Step 125: 111972 + 903 = 112875
Step 126: 112875 + 903 = 113778
Step 127: 113778 + 903 = 114681
Step 128: 114681 + 903 = 115584
Step 129: 115584 + 903 = 116487
Step 130: 116487 + 903 = 117390
Step 131: 117390 + 903 = 118293

So, 903*131 = 118293