Unfortunately you can’t manually build arrays in Airtable. Arrays are only created by certain field types (primarily lookup and rollup fields), and even there Airtable’s array processing functions are very limited.
If the fields containing those values are in a single record, you can use the SUM() function:
SUM({Field1}, {Field2}, {Field3})
This won’t work between records because of Airtable’s database-like behavior. Records can’t directly reference other records without being linked. If you’re looking to tally the values across several records, would you mind sharing more details about your use case? There may be other ways to pull it off, but knowing about the design of your base will help us to offer the most appropriate solution(s).
