Ok so I have product sales performance ranking that is used to identify a category into which the sales ranked product falls. Based the following groups.
Sales ranking 1 to 50 is category A
Sales ranking 51 to 100 is category B and so on up to > 1000.
I am using the formula below in Excel but having difficulty is getting this or similar to work in Ragic. Can anyone suggest a fix?

To clarify:
Are you saying that the filed equivalent to the one you have in Excel [@[Item-Store Rank (Last 6WK Sls)]] is in a record in Ragic, and it already has the ranking value: 1-1000?
And you want a formula that can tell you if i should be in category A-G?

If your field is in A1 (make sure it’s in number field type)
And you want the category in A2.
You should be able to achieve similar result by the following formula in A2.