Number Rabge Break up

[yeshuawatso]

I work for a telecommunications company and I'm needing a little help with getting started solving a consistent problem.

In telecomunications a lot of our phone numbers come in ranges (i.e. 555-555-5500 -- 5599; this is a block of 100 since 5500 is the first number). Often these ranges get broken apart and can get a little confusing on what numbers where left in the range.

I was wondering if you guys could point me in the direction on how to either code this or make a formula for it. I have provided an example of the problem that I need to solve below.

Original Block(555-555-2315 -- 2415) Tn 555-555-2372 and 555-555-2349 tns are being reassigned to another customer. 555-555-2315 -- 2348, 555-555-2350 -- 2371, 555-555-2373 -- 2415 are to be left.