SUM of values in a comma delimited cell

The point being made is whether or not the "Numbers" are always single digits.

One approach would be to use a Name... insert a new name as follows:

Name: EVAL
RefersTo =Evaluate("SUM("&INDIRECT("RC[-1]",FALSE)&")")

Then

B1: =EVAL
where A1 holds delimited string

EDIT: the above is just another variant on martin's prior post