OK, let's work through this together. We're starting with 313 and we're going to multiply it by 124, which means we add 313 to itself 124 times.
Step 1: 0 + 313 = 313
Step 2: 313 + 313 = 626
Step 3: 626 + 313 = 939
Step 4: 939 + 313 = 1252
Step 5: 1252 + 313 = 1565
Step 6: 1565 + 313 = 1878
Step 7: 1878 + 313 = 2191
Step 8: 2191 + 313 = 2504
Step 9: 2504 + 313 = 2817
Step 10: 2817 + 313 = 3130
Step 11: 3130 + 313 = 3443
Step 12: 3443 + 313 = 3756
Step 13: 3756 + 313 = 4069
Step 14: 4069 + 313 = 4382
Step 15: 4382 + 313 = 4695
Step 16: 4695 + 313 = 5008
Step 17: 5008 + 313 = 5321
Step 18: 5321 + 313 = 5634
Step 19: 5634 + 313 = 5947
Step 20: 5947 + 313 = 6260
Step 21: 6260 + 313 = 6573
Step 22: 6573 + 313 = 6886
Step 23: 6886 + 313 = 7199
Step 24: 7199 + 313 = 7512
Step 25: 7512 + 313 = 7825
Step 26: 7825 + 313 = 8138
Step 27: 8138 + 313 = 8451
Step 28: 8451 + 313 = 8764
Step 29: 8764 + 313 = 9077
Step 30: 9077 + 313 = 9390
Step 31: 9390 + 313 = 9703
Step 32: 9703 + 313 = 10016
Step 33: 10016 + 313 = 10329
Step 34: 10329 + 313 = 10642
Step 35: 10642 + 313 = 10955
Step 36: 10955 + 313 = 11268
Step 37: 11268 + 313 = 11581
Step 38: 11581 + 313 = 11894
Step 39: 11894 + 313 = 12207
Step 40: 12207 + 313 = 12520
Step 41: 12520 + 313 = 12833
Step 42: 12833 + 313 = 13146
Step 43: 13146 + 313 = 13459
Step 44: 13459 + 313 = 13772
Step 45: 13772 + 313 = 14085
Step 46: 14085 + 313 = 14398
Step 47: 14398 + 313 = 14711
Step 48: 14711 + 313 = 15024
Step 49: 15024 + 313 = 15337
Step 50: 15337 + 313 = 15650
Step 51: 15650 + 313 = 15963
Step 52: 15963 + 313 = 16276
Step 53: 16276 + 313 = 16589
Step 54: 16589 + 313 = 16902
Step 55: 16902 + 313 = 17215
Step 56: 17215 + 313 = 17528
Step 57: 17528 + 313 = 17841
Step 58: 17841 + 313 = 18154
Step 59: 18154 + 313 = 18467
Step 60: 18467 + 313 = 18780
Step 61: 18780 + 313 = 19093
Step 62: 19093 + 313 = 19406
Step 63: 19406 + 313 = 19719
Step 64: 19719 + 313 = 20032
Step 65: 20032 + 313 = 20345
Step 66: 20345 + 313 = 20658
Step 67: 20658 + 313 = 20971
Step 68: 20971 + 313 = 21284
Step 69: 21284 + 313 = 21597
Step 70: 21597 + 313 = 21910
Step 71: 21910 + 313 = 22223
Step 72: 22223 + 313 = 22536
Step 73: 22536 + 313 = 22849
Step 74: 22849 + 313 = 23162
Step 75: 23162 + 313 = 23475
Step 76: 23475 + 313 = 23788
Step 77: 23788 + 313 = 24101
Step 78: 24101 + 313 = 24414
Step 79: 24414 + 313 = 24727
Step 80: 24727 + 313 = 25040
Step 81: 25040 + 313 = 25353
Step 82: 25353 + 313 = 25666
Step 83: 25666 + 313 = 25979
Step 84: 25979 + 313 = 26292
Step 85: 26292 + 313 = 26605
Step 86: 26605 + 313 = 26918
Step 87: 26918 + 313 = 27231
Step 88: 27231 + 313 = 27544
Step 89: 27544 + 313 = 27857
Step 90: 27857 + 313 = 28170
Step 91: 28170 + 313 = 28483
Step 92: 28483 + 313 = 28796
Step 93: 28796 + 313 = 29109
Step 94: 29109 + 313 = 29422
Step 95: 29422 + 313 = 29735
Step 96: 29735 + 313 = 30048
Step 97: 30048 + 313 = 30361
Step 98: 30361 + 313 = 30674
Step 99: 30674 + 313 = 30987
Step 100: 30987 + 313 = 31300
Step 101: 31300 + 313 = 31613
Step 102: 31613 + 313 = 31926
Step 103: 31926 + 313 = 32239
Step 104: 32239 + 313 = 32552
Step 105: 32552 + 313 = 32865
Step 106: 32865 + 313 = 33178
Step 107: 33178 + 313 = 33491
Step 108: 33491 + 313 = 33804
Step 109: 33804 + 313 = 34117
Step 110: 34117 + 313 = 34430
Step 111: 34430 + 313 = 34743
Step 112: 34743 + 313 = 35056
Step 113: 35056 + 313 = 35369
Step 114: 35369 + 313 = 35682
Step 115: 35682 + 313 = 35995
Step 116: 35995 + 313 = 36308
Step 117: 36308 + 313 = 36621
Step 118: 36621 + 313 = 36934
Step 119: 36934 + 313 = 37247
Step 120: 37247 + 313 = 37560
Step 121: 37560 + 313 = 37873
Step 122: 37873 + 313 = 38186
Step 123: 38186 + 313 = 38499
Step 124: 38499 + 313 = 38812

So, 313*124 = 38812