This afternoon my husband and I talked about recursion, and we decided to write some recursion functions with different languages. He uses JavaScript, and I use Python.

Here is the simple question: **Please use recursion to revert 12345 to 54321**

**Can you use operations to solve this problem instead of using string?**However, I found there's a problem with running this function. It works when you provide a number like this: But if you provide the number that end with 0, it will cause problem. Because the "Number" cannot start with zero.

Of course there's a way to solve it, but it will be different from what we're looking for from the second question. Not sure if I can figure out a better answer for the second question latter.