OK, let's crack this. We're given 124 and our task is to multiply it by 109. Essentially, we'll be adding 124 to itself 109 times.
Step 1: 0 + 124 = 124
Step 2: 124 + 124 = 248
Step 3: 248 + 124 = 372
Step 4: 372 + 124 = 496
Step 5: 496 + 124 = 620
Step 6: 620 + 124 = 744
Step 7: 744 + 124 = 868
Step 8: 868 + 124 = 992
Step 9: 992 + 124 = 1116
Step 10: 1116 + 124 = 1240
Step 11: 1240 + 124 = 1364
Step 12: 1364 + 124 = 1488
Step 13: 1488 + 124 = 1612
Step 14: 1612 + 124 = 1736
Step 15: 1736 + 124 = 1860
Step 16: 1860 + 124 = 1984
Step 17: 1984 + 124 = 2108
Step 18: 2108 + 124 = 2232
Step 19: 2232 + 124 = 2356
Step 20: 2356 + 124 = 2480
Step 21: 2480 + 124 = 2604
Step 22: 2604 + 124 = 2728
Step 23: 2728 + 124 = 2852
Step 24: 2852 + 124 = 2976
Step 25: 2976 + 124 = 3100
Step 26: 3100 + 124 = 3224
Step 27: 3224 + 124 = 3348
Step 28: 3348 + 124 = 3472
Step 29: 3472 + 124 = 3596
Step 30: 3596 + 124 = 3720
Step 31: 3720 + 124 = 3844
Step 32: 3844 + 124 = 3968
Step 33: 3968 + 124 = 4092
Step 34: 4092 + 124 = 4216
Step 35: 4216 + 124 = 4340
Step 36: 4340 + 124 = 4464
Step 37: 4464 + 124 = 4588
Step 38: 4588 + 124 = 4712
Step 39: 4712 + 124 = 4836
Step 40: 4836 + 124 = 4960
Step 41: 4960 + 124 = 5084
Step 42: 5084 + 124 = 5208
Step 43: 5208 + 124 = 5332
Step 44: 5332 + 124 = 5456
Step 45: 5456 + 124 = 5580
Step 46: 5580 + 124 = 5704
Step 47: 5704 + 124 = 5828
Step 48: 5828 + 124 = 5952
Step 49: 5952 + 124 = 6076
Step 50: 6076 + 124 = 6200
Step 51: 6200 + 124 = 6324
Step 52: 6324 + 124 = 6448
Step 53: 6448 + 124 = 6572
Step 54: 6572 + 124 = 6696
Step 55: 6696 + 124 = 6820
Step 56: 6820 + 124 = 6944
Step 57: 6944 + 124 = 7068
Step 58: 7068 + 124 = 7192
Step 59: 7192 + 124 = 7316
Step 60: 7316 + 124 = 7440
Step 61: 7440 + 124 = 7564
Step 62: 7564 + 124 = 7688
Step 63: 7688 + 124 = 7812
Step 64: 7812 + 124 = 7936
Step 65: 7936 + 124 = 8060
Step 66: 8060 + 124 = 8184
Step 67: 8184 + 124 = 8308
Step 68: 8308 + 124 = 8432
Step 69: 8432 + 124 = 8556
Step 70: 8556 + 124 = 8680
Step 71: 8680 + 124 = 8804
Step 72: 8804 + 124 = 8928
Step 73: 8928 + 124 = 9052
Step 74: 9052 + 124 = 9176
Step 75: 9176 + 124 = 9300
Step 76: 9300 + 124 = 9424
Step 77: 9424 + 124 = 9548
Step 78: 9548 + 124 = 9672
Step 79: 9672 + 124 = 9796
Step 80: 9796 + 124 = 9920
Step 81: 9920 + 124 = 10044
Step 82: 10044 + 124 = 10168
Step 83: 10168 + 124 = 10292
Step 84: 10292 + 124 = 10416
Step 85: 10416 + 124 = 10540
Step 86: 10540 + 124 = 10664
Step 87: 10664 + 124 = 10788
Step 88: 10788 + 124 = 10912
Step 89: 10912 + 124 = 11036
Step 90: 11036 + 124 = 11160
Step 91: 11160 + 124 = 11284
Step 92: 11284 + 124 = 11408
Step 93: 11408 + 124 = 11532
Step 94: 11532 + 124 = 11656
Step 95: 11656 + 124 = 11780
Step 96: 11780 + 124 = 11904
Step 97: 11904 + 124 = 12028
Step 98: 12028 + 124 = 12152
Step 99: 12152 + 124 = 12276
Step 100: 12276 + 124 = 12400
Step 101: 12400 + 124 = 12524
Step 102: 12524 + 124 = 12648
Step 103: 12648 + 124 = 12772
Step 104: 12772 + 124 = 12896
Step 105: 12896 + 124 = 13020
Step 106: 13020 + 124 = 13144
Step 107: 13144 + 124 = 13268
Step 108: 13268 + 124 = 13392
Step 109: 13392 + 124 = 13516

So, 124*109 = 13516