A **cryptarithm** is a mathematical puzzle where the digits in a sum have been replaced by letters.

In each of the puzzles below, each letter stands for a different digit.

Bearing in mind that none of the numbers below have 0 as a leading digit, can you find a solution to all of these cryptharithms?

Do any of them have more than one solution?

1. |
2. |
3. |
4. |
||||

5. |
6. |
7. |
8. |
||||

9. |
10. |
11. |
12. |
||||

13. |
14. |
15. |
16. |
||||

17. |
18. |
19. |
20. |
||||

21. |
22. |
23. |

Here is a link to a printable worksheet of this problem.

**Final Challenge**

Is it possible for all of the digits 1 to 9 to appear exactly once in the addition below?

# # #

__+ # # #__

# # #

# # #

Using each digit from 1 to 9 once, what is the largest sum you can obtain in the addition above?

*If you enjoyed this problem, you may also like to take a look at Two and Two.*

*With thanks to Don Steward, whose ideas formed the basis of this problem.*