Lookup multiple values in excel

I'm trying to use excel to lookup multiple values and add them together. I want to be able to put the range in two cells then get the corresponding values on the table for two numbers at the ends of the range and all of them in between.

For example, I would like to be able to put a 1 in one box and a 5 in the other box then have lookup get all the values from the table for 1, 2, 3, 4, and 5 then add them together. Is there any way to do this?

nevermind. figured out I can just use =SUM(INDIRECT("Sheet8!B"&A1):INDIRECT("Sheet8!B"&A2))