Addition inside a string

hello,

anyone knows how to do this:

given a=0, i want to print in next line that a=1 so how do I do that inside the string?

ex.
a=0
b="value of a=$((a+1))"? <- Because this is incorrect..

Thanks!

It certainly is correct. What shell are you in, on what OS?

$ a=0
$ b="value of a=$((a+1))"
$ echo "$b"
value of a=1