Alright, let's solve this math problem step by step. First, we have the number 899. Next, we see the multiplication sign, which means we need to multiply something. And what are we multiplying it by? We multiply it by 138. So, we're going to take the number 899 and add it to itself 138 times.
Step 1: 0 + 899 = 899
Step 2: 899 + 899 = 1798
Step 3: 1798 + 899 = 2697
Step 4: 2697 + 899 = 3596
Step 5: 3596 + 899 = 4495
Step 6: 4495 + 899 = 5394
Step 7: 5394 + 899 = 6293
Step 8: 6293 + 899 = 7192
Step 9: 7192 + 899 = 8091
Step 10: 8091 + 899 = 8990
Step 11: 8990 + 899 = 9889
Step 12: 9889 + 899 = 10788
Step 13: 10788 + 899 = 11687
Step 14: 11687 + 899 = 12586
Step 15: 12586 + 899 = 13485
Step 16: 13485 + 899 = 14384
Step 17: 14384 + 899 = 15283
Step 18: 15283 + 899 = 16182
Step 19: 16182 + 899 = 17081
Step 20: 17081 + 899 = 17980
Step 21: 17980 + 899 = 18879
Step 22: 18879 + 899 = 19778
Step 23: 19778 + 899 = 20677
Step 24: 20677 + 899 = 21576
Step 25: 21576 + 899 = 22475
Step 26: 22475 + 899 = 23374
Step 27: 23374 + 899 = 24273
Step 28: 24273 + 899 = 25172
Step 29: 25172 + 899 = 26071
Step 30: 26071 + 899 = 26970
Step 31: 26970 + 899 = 27869
Step 32: 27869 + 899 = 28768
Step 33: 28768 + 899 = 29667
Step 34: 29667 + 899 = 30566
Step 35: 30566 + 899 = 31465
Step 36: 31465 + 899 = 32364
Step 37: 32364 + 899 = 33263
Step 38: 33263 + 899 = 34162
Step 39: 34162 + 899 = 35061
Step 40: 35061 + 899 = 35960
Step 41: 35960 + 899 = 36859
Step 42: 36859 + 899 = 37758
Step 43: 37758 + 899 = 38657
Step 44: 38657 + 899 = 39556
Step 45: 39556 + 899 = 40455
Step 46: 40455 + 899 = 41354
Step 47: 41354 + 899 = 42253
Step 48: 42253 + 899 = 43152
Step 49: 43152 + 899 = 44051
Step 50: 44051 + 899 = 44950
Step 51: 44950 + 899 = 45849
Step 52: 45849 + 899 = 46748
Step 53: 46748 + 899 = 47647
Step 54: 47647 + 899 = 48546
Step 55: 48546 + 899 = 49445
Step 56: 49445 + 899 = 50344
Step 57: 50344 + 899 = 51243
Step 58: 51243 + 899 = 52142
Step 59: 52142 + 899 = 53041
Step 60: 53041 + 899 = 53940
Step 61: 53940 + 899 = 54839
Step 62: 54839 + 899 = 55738
Step 63: 55738 + 899 = 56637
Step 64: 56637 + 899 = 57536
Step 65: 57536 + 899 = 58435
Step 66: 58435 + 899 = 59334
Step 67: 59334 + 899 = 60233
Step 68: 60233 + 899 = 61132
Step 69: 61132 + 899 = 62031
Step 70: 62031 + 899 = 62930
Step 71: 62930 + 899 = 63829
Step 72: 63829 + 899 = 64728
Step 73: 64728 + 899 = 65627
Step 74: 65627 + 899 = 66526
Step 75: 66526 + 899 = 67425
Step 76: 67425 + 899 = 68324
Step 77: 68324 + 899 = 69223
Step 78: 69223 + 899 = 70122
Step 79: 70122 + 899 = 71021
Step 80: 71021 + 899 = 71920
Step 81: 71920 + 899 = 72819
Step 82: 72819 + 899 = 73718
Step 83: 73718 + 899 = 74617
Step 84: 74617 + 899 = 75516
Step 85: 75516 + 899 = 76415
Step 86: 76415 + 899 = 77314
Step 87: 77314 + 899 = 78213
Step 88: 78213 + 899 = 79112
Step 89: 79112 + 899 = 80011
Step 90: 80011 + 899 = 80910
Step 91: 80910 + 899 = 81809
Step 92: 81809 + 899 = 82708
Step 93: 82708 + 899 = 83607
Step 94: 83607 + 899 = 84506
Step 95: 84506 + 899 = 85405
Step 96: 85405 + 899 = 86304
Step 97: 86304 + 899 = 87203
Step 98: 87203 + 899 = 88102
Step 99: 88102 + 899 = 89001
Step 100: 89001 + 899 = 89900
Step 101: 89900 + 899 = 90799
Step 102: 90799 + 899 = 91698
Step 103: 91698 + 899 = 92597
Step 104: 92597 + 899 = 93496
Step 105: 93496 + 899 = 94395
Step 106: 94395 + 899 = 95294
Step 107: 95294 + 899 = 96193
Step 108: 96193 + 899 = 97092
Step 109: 97092 + 899 = 97991
Step 110: 97991 + 899 = 98890
Step 111: 98890 + 899 = 99789
Step 112: 99789 + 899 = 100688
Step 113: 100688 + 899 = 101587
Step 114: 101587 + 899 = 102486
Step 115: 102486 + 899 = 103385
Step 116: 103385 + 899 = 104284
Step 117: 104284 + 899 = 105183
Step 118: 105183 + 899 = 106082
Step 119: 106082 + 899 = 106981
Step 120: 106981 + 899 = 107880
Step 121: 107880 + 899 = 108779
Step 122: 108779 + 899 = 109678
Step 123: 109678 + 899 = 110577
Step 124: 110577 + 899 = 111476
Step 125: 111476 + 899 = 112375
Step 126: 112375 + 899 = 113274
Step 127: 113274 + 899 = 114173
Step 128: 114173 + 899 = 115072
Step 129: 115072 + 899 = 115971
Step 130: 115971 + 899 = 116870
Step 131: 116870 + 899 = 117769
Step 132: 117769 + 899 = 118668
Step 133: 118668 + 899 = 119567
Step 134: 119567 + 899 = 120466
Step 135: 120466 + 899 = 121365
Step 136: 121365 + 899 = 122264
Step 137: 122264 + 899 = 123163
Step 138: 123163 + 899 = 124062

So, 899*138 = 124062