Expression (1 Viewer)

Hello World,I have two tables one named Correct_Add and the other New_Add. In each table I have the same categories Weight, Height etc. I want to find the percentage difference between each category. I know I need to write an expression but I am a little confused on the format. Right now I have =(("Correct_Add-New_Add")/("Correct_Add"))*100 obviously this is not correct because the categories are not specified which is the part I am confused about. Any help is appreciatedThanks