BH,
I did format the values as numbers, but that alone did not do the trick.
FYI: Formatting cells as numbers will not solve a data type problem because the number formatting has four elements: 'positive format';'negative format';'zero format';'text format'
So a number format will happily display text. What you usually notice is that numbers are right aligned in a cell and text is left aligned, but this will not happen where the cells have been manually formatted eg centred.
BTW: CHOOSE is considered a bit of a legacy function held over for compatibility with older versions of Excel. The more modern approach is to use a combination of the INDEX and MATCH functions with a data table. However, given your expressed level of skill I would just stick with what works for you.
HTH
EG