A cryptarithm is an arithmetic puzzle in which each digit of a fundamental operation is assigned a definite letter as in a code.
The challenge is to break the code.
These problems require skilful use of logic, & the knowledge of number theory & algebra.
The task of creating a cryptarithmic puzzle is difficult & a challenging one. As you will see in subsequent problems, the problems are skilfully designed so that actual words from the dictionary appear in the problem.
In the beginning, the task may look a challenging one, but after some practice, you will find that the solution comes naturally to you.
One reason I have not included complete steps of solving these problems is that they are too large. It takes a great amount of time & considerable space to be able to write a complete solution to cryptarithmic puzzle.
Start & try to attack these problems right on!