Alright, let's solve this math problem step by step. First, we have the number 155. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 123. So, we're going to take the number 155 and add it to itself 123 times.
Step 1: 0 + 155 = 155
Step 2: 155 + 155 = 310
Step 3: 310 + 155 = 465
Step 4: 465 + 155 = 620
Step 5: 620 + 155 = 775
Step 6: 775 + 155 = 930
Step 7: 930 + 155 = 1085
Step 8: 1085 + 155 = 1240
Step 9: 1240 + 155 = 1395
Step 10: 1395 + 155 = 1550
Step 11: 1550 + 155 = 1705
Step 12: 1705 + 155 = 1860
Step 13: 1860 + 155 = 2015
Step 14: 2015 + 155 = 2170
Step 15: 2170 + 155 = 2325
Step 16: 2325 + 155 = 2480
Step 17: 2480 + 155 = 2635
Step 18: 2635 + 155 = 2790
Step 19: 2790 + 155 = 2945
Step 20: 2945 + 155 = 3100
Step 21: 3100 + 155 = 3255
Step 22: 3255 + 155 = 3410
Step 23: 3410 + 155 = 3565
Step 24: 3565 + 155 = 3720
Step 25: 3720 + 155 = 3875
Step 26: 3875 + 155 = 4030
Step 27: 4030 + 155 = 4185
Step 28: 4185 + 155 = 4340
Step 29: 4340 + 155 = 4495
Step 30: 4495 + 155 = 4650
Step 31: 4650 + 155 = 4805
Step 32: 4805 + 155 = 4960
Step 33: 4960 + 155 = 5115
Step 34: 5115 + 155 = 5270
Step 35: 5270 + 155 = 5425
Step 36: 5425 + 155 = 5580
Step 37: 5580 + 155 = 5735
Step 38: 5735 + 155 = 5890
Step 39: 5890 + 155 = 6045
Step 40: 6045 + 155 = 6200
Step 41: 6200 + 155 = 6355
Step 42: 6355 + 155 = 6510
Step 43: 6510 + 155 = 6665
Step 44: 6665 + 155 = 6820
Step 45: 6820 + 155 = 6975
Step 46: 6975 + 155 = 7130
Step 47: 7130 + 155 = 7285
Step 48: 7285 + 155 = 7440
Step 49: 7440 + 155 = 7595
Step 50: 7595 + 155 = 7750
Step 51: 7750 + 155 = 7905
Step 52: 7905 + 155 = 8060
Step 53: 8060 + 155 = 8215
Step 54: 8215 + 155 = 8370
Step 55: 8370 + 155 = 8525
Step 56: 8525 + 155 = 8680
Step 57: 8680 + 155 = 8835
Step 58: 8835 + 155 = 8990
Step 59: 8990 + 155 = 9145
Step 60: 9145 + 155 = 9300
Step 61: 9300 + 155 = 9455
Step 62: 9455 + 155 = 9610
Step 63: 9610 + 155 = 9765
Step 64: 9765 + 155 = 9920
Step 65: 9920 + 155 = 10075
Step 66: 10075 + 155 = 10230
Step 67: 10230 + 155 = 10385
Step 68: 10385 + 155 = 10540
Step 69: 10540 + 155 = 10695
Step 70: 10695 + 155 = 10850
Step 71: 10850 + 155 = 11005
Step 72: 11005 + 155 = 11160
Step 73: 11160 + 155 = 11315
Step 74: 11315 + 155 = 11470
Step 75: 11470 + 155 = 11625
Step 76: 11625 + 155 = 11780
Step 77: 11780 + 155 = 11935
Step 78: 11935 + 155 = 12090
Step 79: 12090 + 155 = 12245
Step 80: 12245 + 155 = 12400
Step 81: 12400 + 155 = 12555
Step 82: 12555 + 155 = 12710
Step 83: 12710 + 155 = 12865
Step 84: 12865 + 155 = 13020
Step 85: 13020 + 155 = 13175
Step 86: 13175 + 155 = 13330
Step 87: 13330 + 155 = 13485
Step 88: 13485 + 155 = 13640
Step 89: 13640 + 155 = 13795
Step 90: 13795 + 155 = 13950
Step 91: 13950 + 155 = 14105
Step 92: 14105 + 155 = 14260
Step 93: 14260 + 155 = 14415
Step 94: 14415 + 155 = 14570
Step 95: 14570 + 155 = 14725
Step 96: 14725 + 155 = 14880
Step 97: 14880 + 155 = 15035
Step 98: 15035 + 155 = 15190
Step 99: 15190 + 155 = 15345
Step 100: 15345 + 155 = 15500
Step 101: 15500 + 155 = 15655
Step 102: 15655 + 155 = 15810
Step 103: 15810 + 155 = 15965
Step 104: 15965 + 155 = 16120
Step 105: 16120 + 155 = 16275
Step 106: 16275 + 155 = 16430
Step 107: 16430 + 155 = 16585
Step 108: 16585 + 155 = 16740
Step 109: 16740 + 155 = 16895
Step 110: 16895 + 155 = 17050
Step 111: 17050 + 155 = 17205
Step 112: 17205 + 155 = 17360
Step 113: 17360 + 155 = 17515
Step 114: 17515 + 155 = 17670
Step 115: 17670 + 155 = 17825
Step 116: 17825 + 155 = 17980
Step 117: 17980 + 155 = 18135
Step 118: 18135 + 155 = 18290
Step 119: 18290 + 155 = 18445
Step 120: 18445 + 155 = 18600
Step 121: 18600 + 155 = 18755
Step 122: 18755 + 155 = 18910
Step 123: 18910 + 155 = 19065

So, 155*123 = 19065