Alright, let's solve this math problem step by step. First, we have the number 399. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 150. So, we're going to take the number 399 and add it to itself 150 times.
Step 1: 0 + 399 = 399
Step 2: 399 + 399 = 798
Step 3: 798 + 399 = 1197
Step 4: 1197 + 399 = 1596
Step 5: 1596 + 399 = 1995
Step 6: 1995 + 399 = 2394
Step 7: 2394 + 399 = 2793
Step 8: 2793 + 399 = 3192
Step 9: 3192 + 399 = 3591
Step 10: 3591 + 399 = 3990
Step 11: 3990 + 399 = 4389
Step 12: 4389 + 399 = 4788
Step 13: 4788 + 399 = 5187
Step 14: 5187 + 399 = 5586
Step 15: 5586 + 399 = 5985
Step 16: 5985 + 399 = 6384
Step 17: 6384 + 399 = 6783
Step 18: 6783 + 399 = 7182
Step 19: 7182 + 399 = 7581
Step 20: 7581 + 399 = 7980
Step 21: 7980 + 399 = 8379
Step 22: 8379 + 399 = 8778
Step 23: 8778 + 399 = 9177
Step 24: 9177 + 399 = 9576
Step 25: 9576 + 399 = 9975
Step 26: 9975 + 399 = 10374
Step 27: 10374 + 399 = 10773
Step 28: 10773 + 399 = 11172
Step 29: 11172 + 399 = 11571
Step 30: 11571 + 399 = 11970
Step 31: 11970 + 399 = 12369
Step 32: 12369 + 399 = 12768
Step 33: 12768 + 399 = 13167
Step 34: 13167 + 399 = 13566
Step 35: 13566 + 399 = 13965
Step 36: 13965 + 399 = 14364
Step 37: 14364 + 399 = 14763
Step 38: 14763 + 399 = 15162
Step 39: 15162 + 399 = 15561
Step 40: 15561 + 399 = 15960
Step 41: 15960 + 399 = 16359
Step 42: 16359 + 399 = 16758
Step 43: 16758 + 399 = 17157
Step 44: 17157 + 399 = 17556
Step 45: 17556 + 399 = 17955
Step 46: 17955 + 399 = 18354
Step 47: 18354 + 399 = 18753
Step 48: 18753 + 399 = 19152
Step 49: 19152 + 399 = 19551
Step 50: 19551 + 399 = 19950
Step 51: 19950 + 399 = 20349
Step 52: 20349 + 399 = 20748
Step 53: 20748 + 399 = 21147
Step 54: 21147 + 399 = 21546
Step 55: 21546 + 399 = 21945
Step 56: 21945 + 399 = 22344
Step 57: 22344 + 399 = 22743
Step 58: 22743 + 399 = 23142
Step 59: 23142 + 399 = 23541
Step 60: 23541 + 399 = 23940
Step 61: 23940 + 399 = 24339
Step 62: 24339 + 399 = 24738
Step 63: 24738 + 399 = 25137
Step 64: 25137 + 399 = 25536
Step 65: 25536 + 399 = 25935
Step 66: 25935 + 399 = 26334
Step 67: 26334 + 399 = 26733
Step 68: 26733 + 399 = 27132
Step 69: 27132 + 399 = 27531
Step 70: 27531 + 399 = 27930
Step 71: 27930 + 399 = 28329
Step 72: 28329 + 399 = 28728
Step 73: 28728 + 399 = 29127
Step 74: 29127 + 399 = 29526
Step 75: 29526 + 399 = 29925
Step 76: 29925 + 399 = 30324
Step 77: 30324 + 399 = 30723
Step 78: 30723 + 399 = 31122
Step 79: 31122 + 399 = 31521
Step 80: 31521 + 399 = 31920
Step 81: 31920 + 399 = 32319
Step 82: 32319 + 399 = 32718
Step 83: 32718 + 399 = 33117
Step 84: 33117 + 399 = 33516
Step 85: 33516 + 399 = 33915
Step 86: 33915 + 399 = 34314
Step 87: 34314 + 399 = 34713
Step 88: 34713 + 399 = 35112
Step 89: 35112 + 399 = 35511
Step 90: 35511 + 399 = 35910
Step 91: 35910 + 399 = 36309
Step 92: 36309 + 399 = 36708
Step 93: 36708 + 399 = 37107
Step 94: 37107 + 399 = 37506
Step 95: 37506 + 399 = 37905
Step 96: 37905 + 399 = 38304
Step 97: 38304 + 399 = 38703
Step 98: 38703 + 399 = 39102
Step 99: 39102 + 399 = 39501
Step 100: 39501 + 399 = 39900
Step 101: 39900 + 399 = 40299
Step 102: 40299 + 399 = 40698
Step 103: 40698 + 399 = 41097
Step 104: 41097 + 399 = 41496
Step 105: 41496 + 399 = 41895
Step 106: 41895 + 399 = 42294
Step 107: 42294 + 399 = 42693
Step 108: 42693 + 399 = 43092
Step 109: 43092 + 399 = 43491
Step 110: 43491 + 399 = 43890
Step 111: 43890 + 399 = 44289
Step 112: 44289 + 399 = 44688
Step 113: 44688 + 399 = 45087
Step 114: 45087 + 399 = 45486
Step 115: 45486 + 399 = 45885
Step 116: 45885 + 399 = 46284
Step 117: 46284 + 399 = 46683
Step 118: 46683 + 399 = 47082
Step 119: 47082 + 399 = 47481
Step 120: 47481 + 399 = 47880
Step 121: 47880 + 399 = 48279
Step 122: 48279 + 399 = 48678
Step 123: 48678 + 399 = 49077
Step 124: 49077 + 399 = 49476
Step 125: 49476 + 399 = 49875
Step 126: 49875 + 399 = 50274
Step 127: 50274 + 399 = 50673
Step 128: 50673 + 399 = 51072
Step 129: 51072 + 399 = 51471
Step 130: 51471 + 399 = 51870
Step 131: 51870 + 399 = 52269
Step 132: 52269 + 399 = 52668
Step 133: 52668 + 399 = 53067
Step 134: 53067 + 399 = 53466
Step 135: 53466 + 399 = 53865
Step 136: 53865 + 399 = 54264
Step 137: 54264 + 399 = 54663
Step 138: 54663 + 399 = 55062
Step 139: 55062 + 399 = 55461
Step 140: 55461 + 399 = 55860
Step 141: 55860 + 399 = 56259
Step 142: 56259 + 399 = 56658
Step 143: 56658 + 399 = 57057
Step 144: 57057 + 399 = 57456
Step 145: 57456 + 399 = 57855
Step 146: 57855 + 399 = 58254
Step 147: 58254 + 399 = 58653
Step 148: 58653 + 399 = 59052
Step 149: 59052 + 399 = 59451
Step 150: 59451 + 399 = 59850

So, 399*150 = 59850