Basic formula challenge: wrong argument type


I am new here and trying to do some basic math across some tables.

I have the current formula


The first number is in another column on the same table
The other two columns are from lookup columns, which are currently showing the number that i want to add (i.e., display column from the table that i got)

I get the wrong sum value when I have the three numbers on the formula. However, if I use only two of them, I get the right number.


The second and third values are lists of row references and not numbers (look at the little icon on the right) - this is what you need to fix.
The solution depends on what data you actually have in these columns, so it would be easier to help you if you’ll embed a dummy version of your doc here or at least some informative screen shots.