brekup

Does anyone know what a breakup function is?
It's supposed to "break up and put back together a number"?
help me out!

Let's say you have the number 12345 and you want to "break up" the number into individual digits or a set two numbers the first consisting of the first two digits and the second consisting of the last three digits. How would you do that? That is what I think is meant by a break up function. It might also apply to a float where you "break up" a number such as 12.345 into two numbers like 12 and 345. In any event there is no standard "break up" function which means you are on your own.

Thanks fo your input