The mother wrote back:
As in 1160.11, each letter stands for a numeral (0 1 2 3 4 5 6 7 8 or 9). The same letter always stands for the same numeral and two different letters never stand for the same numeral. Your job is to figure out what each letter stands for.
Solution
There are two solutions that we know of.
1: A = 5, C = 9, E = 4, H = 6, L = 1, M = 2, N = 3, O = 8, R = 0, and S = 7.
2: A = 1, C = 7, E = 5, H = 9, L = 3, M = 2, N = 8, O = 6, R = 0, and S = 4.
(There are rumors of a 3rd solution with C = 8. If you find it, let us know.)
This problem naturally follows after 1160.11. There is a very lengthy explanation of the solution to that problem, which you could use to develop the solution to this one.