Comparing columns accross spreadsheets

Hi all,

I've been given a large spreadsheet (A) of order numbers which for some reason have had the last digit removed. My task is to get the last digit added. To do so manually would take an age. My problem is the order numbers on (A) are scattered throughout other five other workbooks (B).

Ideally I'd like to do something using concatenate to merge the two together but the problem so far is I don't have two list which match. Perhaps that's the first step?

I had initially hoped to narrow the search by using countif and a wildcard but to do so it seems I need to manually enter order like below

=countif(sheet x A1:Z500,"12345*")

Ideally I'd like to do the below

=countif(sheet x A1:Z500,A1*)

Any thoughts or better ideas?

Thanks