Letter Number Cipher

One of the first ciphers that kids learn is a letter number cipher. It is a simple substitution cipher where you replace letters with a number: A=1, B=2, C=3, etc. The complete cipher looks like this


So for example if our message was “x marks the spot”

The cipher would be
24 13 1 18 11 19 20 8 5 19 16 15 20