Mathematics Packs 1A 1B 1C 1D

I was a lucky boy last week. I got a new HP 41 CX!
Now I'm looking for a Math Pack.
What is the difference of the Mathematics Packs 1A 1B 1C 1D
Thanks for your information

Now I'm looking for a Math Pack.
What is the difference of the Mathematics Packs 1A 1B 1C 1D

Thanks for your information