Is it mathematically possible to break a number into 2 parts using information you used to combine them? Im not a math person. Here goes.
Bob has 2 numbers A & B.
Bob used a detailed process which takes A & B as inputs, and results C
The process does not store A or B.
A (process) B = C

Can Jack use the detailed step-by-step process to convert C back into A and B ?
Is  it possible to define a set of rules such that the above is possible?
 A: In most situations, no. The (process) can't be addition or multiplication since you can't find the summands or factors knowing just the sum or product.
There are special cases. For example, if you know each of the numbers is an integer and $A$ and $B$ are less than $1000$ and you let
$$
C = 1000A + B
$$
then knowing $C$ tells you both $A$ and $B$.
If you have some particular previous question that led to this one, ask that question.
Edit. Your comment suggests that a solution like the one I proposed above may work. If $A$ and $B$ are both known to be integers less than some bound $M$ then with
$$
C = AM + B
$$
you know $B = C \% M$ and $A = (C-B)/M$.
This works because  $C$ is a two digit number in base $M$ with digits $A$ and $B$.
Edit in answer to comment.
"$C = 100$" is  not all the information. To find $A$ and $B$ you need to know both $C$ and the a priori bound $M$ (independent of $A$ and $B$).
For example, if $C=100$ and $M=50$ then $100$ in base $50$ is the two digit number "$20$" since $100 = 2 \times 50 + 0$ so $A=2$ and $B=0$.
A: The classic method here takes any number of numbers $A$, $B$, $C$, $D$, $E$,… raises primes to those powers and multiplies them: $$RESULT=2^A 3^B 5^C 7^D 11^E…$$
The reverse process is the prime factorisation of $RESULT$.
In the way I have described it, the numbers all need to be greater than zero, but it is easy enough to add 1 to each of them before multiplication. One more minor adjustment, and you have found a way of packing any finite sequence of numbers, of any [finite] length, into a single number. Which proves that there are "as many" finite sequences of numbers as there are numbers. 
