I had a TI-83+, not a TI-83, so I can't be sure but I suspect you're misremember...

Izkata on July 31, 2022 | parent | context | favorite | on: TI-83 Plus One More

I had a TI-83+, not a TI-83, so I can't be sure but I suspect you're misremembering which feature was missing: The + did have while loops but didn't have functions, but calling another program worked like a function call with no parameters and no return value (and you could fake both by using the global variables).

krallja on July 31, 2022 [–]

`Ans` stored the value of the last expression, so you could use that as a “return value” of sorts.