Alright, let's solve this math problem step by step. First, we have the number 151. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 139. So, we're going to take the number 151 and add it to itself 139 times.
Step 1: 0 + 151 = 151
Step 2: 151 + 151 = 302
Step 3: 302 + 151 = 453
Step 4: 453 + 151 = 604
Step 5: 604 + 151 = 755
Step 6: 755 + 151 = 906
Step 7: 906 + 151 = 1057
Step 8: 1057 + 151 = 1208
Step 9: 1208 + 151 = 1359
Step 10: 1359 + 151 = 1510
Step 11: 1510 + 151 = 1661
Step 12: 1661 + 151 = 1812
Step 13: 1812 + 151 = 1963
Step 14: 1963 + 151 = 2114
Step 15: 2114 + 151 = 2265
Step 16: 2265 + 151 = 2416
Step 17: 2416 + 151 = 2567
Step 18: 2567 + 151 = 2718
Step 19: 2718 + 151 = 2869
Step 20: 2869 + 151 = 3020
Step 21: 3020 + 151 = 3171
Step 22: 3171 + 151 = 3322
Step 23: 3322 + 151 = 3473
Step 24: 3473 + 151 = 3624
Step 25: 3624 + 151 = 3775
Step 26: 3775 + 151 = 3926
Step 27: 3926 + 151 = 4077
Step 28: 4077 + 151 = 4228
Step 29: 4228 + 151 = 4379
Step 30: 4379 + 151 = 4530
Step 31: 4530 + 151 = 4681
Step 32: 4681 + 151 = 4832
Step 33: 4832 + 151 = 4983
Step 34: 4983 + 151 = 5134
Step 35: 5134 + 151 = 5285
Step 36: 5285 + 151 = 5436
Step 37: 5436 + 151 = 5587
Step 38: 5587 + 151 = 5738
Step 39: 5738 + 151 = 5889
Step 40: 5889 + 151 = 6040
Step 41: 6040 + 151 = 6191
Step 42: 6191 + 151 = 6342
Step 43: 6342 + 151 = 6493
Step 44: 6493 + 151 = 6644
Step 45: 6644 + 151 = 6795
Step 46: 6795 + 151 = 6946
Step 47: 6946 + 151 = 7097
Step 48: 7097 + 151 = 7248
Step 49: 7248 + 151 = 7399
Step 50: 7399 + 151 = 7550
Step 51: 7550 + 151 = 7701
Step 52: 7701 + 151 = 7852
Step 53: 7852 + 151 = 8003
Step 54: 8003 + 151 = 8154
Step 55: 8154 + 151 = 8305
Step 56: 8305 + 151 = 8456
Step 57: 8456 + 151 = 8607
Step 58: 8607 + 151 = 8758
Step 59: 8758 + 151 = 8909
Step 60: 8909 + 151 = 9060
Step 61: 9060 + 151 = 9211
Step 62: 9211 + 151 = 9362
Step 63: 9362 + 151 = 9513
Step 64: 9513 + 151 = 9664
Step 65: 9664 + 151 = 9815
Step 66: 9815 + 151 = 9966
Step 67: 9966 + 151 = 10117
Step 68: 10117 + 151 = 10268
Step 69: 10268 + 151 = 10419
Step 70: 10419 + 151 = 10570
Step 71: 10570 + 151 = 10721
Step 72: 10721 + 151 = 10872
Step 73: 10872 + 151 = 11023
Step 74: 11023 + 151 = 11174
Step 75: 11174 + 151 = 11325
Step 76: 11325 + 151 = 11476
Step 77: 11476 + 151 = 11627
Step 78: 11627 + 151 = 11778
Step 79: 11778 + 151 = 11929
Step 80: 11929 + 151 = 12080
Step 81: 12080 + 151 = 12231
Step 82: 12231 + 151 = 12382
Step 83: 12382 + 151 = 12533
Step 84: 12533 + 151 = 12684
Step 85: 12684 + 151 = 12835
Step 86: 12835 + 151 = 12986
Step 87: 12986 + 151 = 13137
Step 88: 13137 + 151 = 13288
Step 89: 13288 + 151 = 13439
Step 90: 13439 + 151 = 13590
Step 91: 13590 + 151 = 13741
Step 92: 13741 + 151 = 13892
Step 93: 13892 + 151 = 14043
Step 94: 14043 + 151 = 14194
Step 95: 14194 + 151 = 14345
Step 96: 14345 + 151 = 14496
Step 97: 14496 + 151 = 14647
Step 98: 14647 + 151 = 14798
Step 99: 14798 + 151 = 14949
Step 100: 14949 + 151 = 15100
Step 101: 15100 + 151 = 15251
Step 102: 15251 + 151 = 15402
Step 103: 15402 + 151 = 15553
Step 104: 15553 + 151 = 15704
Step 105: 15704 + 151 = 15855
Step 106: 15855 + 151 = 16006
Step 107: 16006 + 151 = 16157
Step 108: 16157 + 151 = 16308
Step 109: 16308 + 151 = 16459
Step 110: 16459 + 151 = 16610
Step 111: 16610 + 151 = 16761
Step 112: 16761 + 151 = 16912
Step 113: 16912 + 151 = 17063
Step 114: 17063 + 151 = 17214
Step 115: 17214 + 151 = 17365
Step 116: 17365 + 151 = 17516
Step 117: 17516 + 151 = 17667
Step 118: 17667 + 151 = 17818
Step 119: 17818 + 151 = 17969
Step 120: 17969 + 151 = 18120
Step 121: 18120 + 151 = 18271
Step 122: 18271 + 151 = 18422
Step 123: 18422 + 151 = 18573
Step 124: 18573 + 151 = 18724
Step 125: 18724 + 151 = 18875
Step 126: 18875 + 151 = 19026
Step 127: 19026 + 151 = 19177
Step 128: 19177 + 151 = 19328
Step 129: 19328 + 151 = 19479
Step 130: 19479 + 151 = 19630
Step 131: 19630 + 151 = 19781
Step 132: 19781 + 151 = 19932
Step 133: 19932 + 151 = 20083
Step 134: 20083 + 151 = 20234
Step 135: 20234 + 151 = 20385
Step 136: 20385 + 151 = 20536
Step 137: 20536 + 151 = 20687
Step 138: 20687 + 151 = 20838
Step 139: 20838 + 151 = 20989

So, 151*139 = 20989