The way of assigning numbers to an alphametic is not clear to me yet. Have you got any suggestions? 

My advice is: start solving the very easy and easy problems. Then proceed to the intermediary and hard levels. In a cryptarithm, every letter "hides" a specific digit. You have to guess the digits "behind" the letters of the problem. Any time you make a guess you have to substitute the letter for its digit, till you get the whole problem solved. Guessing, is best understood as trying all possible alternative digits (not yet decoded) and finding the only one that fits (matches) the arithmetical set up. Letīs take this very easy problem : AD + DI = DID. Write it this way: A D + D I  D I D D + I = D is the units column on the
right side
A 1 + 1 I  1 I 1 Take a look at the units colum and you will guess that I equals zero. In this column you see that 1 + I = 1 so, if you try all digits not yet decoded, you will find that the only one that matches this pattern is zero. See it?
A 1 + 1 0  1 0 1 Then observe the tens column where we
have A + 1 = 10. So, A must be 9 to fit this pattern. And
substituting the A for 9 we have the whole problem
solved, that is: 9 1 + 1 0  1 0 1 I myself use to write the problem set
up using pencil. Then, to substitute the letters for
numbers, I erase them and rewrite with pencil. You have
to do all these substitutions, one by one, in order to
discover the digits that fit.
