Question about object mods, targets and operators

[RedxYeti]

Im wondering what exact mul + add means. im trying to calculate bash damage of the pipe gun. the base bash damage is 6 and with a certain stocks its 6 with the mult + add of 0.5 to up to 2

 

so i guess my question is, how the does the mul + add affect the base 6 damage?

 

 

my assumption is that it means like 6 + (6 * mult)