Let A = 1,
B = 2,
C = 3,......, Z = 26.
Now,  M = 13 = 4 (remainder obtained after dividing by 9);
S = 19 = 1  (remainder obtained after dividing by 9 twice);
T = 20 = 2   (remainder obtained after dividing by 9 twice);
R = 18 = 9   (remainder obtained after dividing by 9).
So, MASTER = 411259
Similarly, POWDER = 765459.