Let's roll up our sleeves and solve this. We have 998 and we're going to multiply it by 126, essentially adding 998 to itself 126 times.
Step 1: 0 + 998 = 998
Step 2: 998 + 998 = 1996
Step 3: 1996 + 998 = 2994
Step 4: 2994 + 998 = 3992
Step 5: 3992 + 998 = 4990
Step 6: 4990 + 998 = 5988
Step 7: 5988 + 998 = 6986
Step 8: 6986 + 998 = 7984
Step 9: 7984 + 998 = 8982
Step 10: 8982 + 998 = 9980
Step 11: 9980 + 998 = 10978
Step 12: 10978 + 998 = 11976
Step 13: 11976 + 998 = 12974
Step 14: 12974 + 998 = 13972
Step 15: 13972 + 998 = 14970
Step 16: 14970 + 998 = 15968
Step 17: 15968 + 998 = 16966
Step 18: 16966 + 998 = 17964
Step 19: 17964 + 998 = 18962
Step 20: 18962 + 998 = 19960
Step 21: 19960 + 998 = 20958
Step 22: 20958 + 998 = 21956
Step 23: 21956 + 998 = 22954
Step 24: 22954 + 998 = 23952
Step 25: 23952 + 998 = 24950
Step 26: 24950 + 998 = 25948
Step 27: 25948 + 998 = 26946
Step 28: 26946 + 998 = 27944
Step 29: 27944 + 998 = 28942
Step 30: 28942 + 998 = 29940
Step 31: 29940 + 998 = 30938
Step 32: 30938 + 998 = 31936
Step 33: 31936 + 998 = 32934
Step 34: 32934 + 998 = 33932
Step 35: 33932 + 998 = 34930
Step 36: 34930 + 998 = 35928
Step 37: 35928 + 998 = 36926
Step 38: 36926 + 998 = 37924
Step 39: 37924 + 998 = 38922
Step 40: 38922 + 998 = 39920
Step 41: 39920 + 998 = 40918
Step 42: 40918 + 998 = 41916
Step 43: 41916 + 998 = 42914
Step 44: 42914 + 998 = 43912
Step 45: 43912 + 998 = 44910
Step 46: 44910 + 998 = 45908
Step 47: 45908 + 998 = 46906
Step 48: 46906 + 998 = 47904
Step 49: 47904 + 998 = 48902
Step 50: 48902 + 998 = 49900
Step 51: 49900 + 998 = 50898
Step 52: 50898 + 998 = 51896
Step 53: 51896 + 998 = 52894
Step 54: 52894 + 998 = 53892
Step 55: 53892 + 998 = 54890
Step 56: 54890 + 998 = 55888
Step 57: 55888 + 998 = 56886
Step 58: 56886 + 998 = 57884
Step 59: 57884 + 998 = 58882
Step 60: 58882 + 998 = 59880
Step 61: 59880 + 998 = 60878
Step 62: 60878 + 998 = 61876
Step 63: 61876 + 998 = 62874
Step 64: 62874 + 998 = 63872
Step 65: 63872 + 998 = 64870
Step 66: 64870 + 998 = 65868
Step 67: 65868 + 998 = 66866
Step 68: 66866 + 998 = 67864
Step 69: 67864 + 998 = 68862
Step 70: 68862 + 998 = 69860
Step 71: 69860 + 998 = 70858
Step 72: 70858 + 998 = 71856
Step 73: 71856 + 998 = 72854
Step 74: 72854 + 998 = 73852
Step 75: 73852 + 998 = 74850
Step 76: 74850 + 998 = 75848
Step 77: 75848 + 998 = 76846
Step 78: 76846 + 998 = 77844
Step 79: 77844 + 998 = 78842
Step 80: 78842 + 998 = 79840
Step 81: 79840 + 998 = 80838
Step 82: 80838 + 998 = 81836
Step 83: 81836 + 998 = 82834
Step 84: 82834 + 998 = 83832
Step 85: 83832 + 998 = 84830
Step 86: 84830 + 998 = 85828
Step 87: 85828 + 998 = 86826
Step 88: 86826 + 998 = 87824
Step 89: 87824 + 998 = 88822
Step 90: 88822 + 998 = 89820
Step 91: 89820 + 998 = 90818
Step 92: 90818 + 998 = 91816
Step 93: 91816 + 998 = 92814
Step 94: 92814 + 998 = 93812
Step 95: 93812 + 998 = 94810
Step 96: 94810 + 998 = 95808
Step 97: 95808 + 998 = 96806
Step 98: 96806 + 998 = 97804
Step 99: 97804 + 998 = 98802
Step 100: 98802 + 998 = 99800
Step 101: 99800 + 998 = 100798
Step 102: 100798 + 998 = 101796
Step 103: 101796 + 998 = 102794
Step 104: 102794 + 998 = 103792
Step 105: 103792 + 998 = 104790
Step 106: 104790 + 998 = 105788
Step 107: 105788 + 998 = 106786
Step 108: 106786 + 998 = 107784
Step 109: 107784 + 998 = 108782
Step 110: 108782 + 998 = 109780
Step 111: 109780 + 998 = 110778
Step 112: 110778 + 998 = 111776
Step 113: 111776 + 998 = 112774
Step 114: 112774 + 998 = 113772
Step 115: 113772 + 998 = 114770
Step 116: 114770 + 998 = 115768
Step 117: 115768 + 998 = 116766
Step 118: 116766 + 998 = 117764
Step 119: 117764 + 998 = 118762
Step 120: 118762 + 998 = 119760
Step 121: 119760 + 998 = 120758
Step 122: 120758 + 998 = 121756
Step 123: 121756 + 998 = 122754
Step 124: 122754 + 998 = 123752
Step 125: 123752 + 998 = 124750
Step 126: 124750 + 998 = 125748

So, 998*126 = 125748