Super newb macro question

Hey gents - looking for some help for what I assume is a dead easy macro.   Here's what I'm trying to do:   User activates the macro.   macro spawns a dialogue box requesting an input for a skill level macro rolls a d100 macro calculates the difference between the d100 roll and the skill level D100 roll, skill level, and margin of difference printed in the chat window Here's what I've been trying.  What I can't seem to figure out is the syntax to calculate the margin.   &{template:default} {{name=Calculate Margin}} {{Rolled=[[d100]]}} {{Skill Rating = [[?{Skill Rating| 50}]]}}  {{Margin =  [[Skill Rating - Rolled)]]}} Any help appreciated. 

Hi John, try this using the " Resusing Rolls " trick; &{template:default} {{name=Calculate Margin}} [[ [[?{Skill Rating| 50}]] - [[1d100]] ]] {{Rolled=$[[1]]}} {{Skill Rating = $[[0]]}} {{Margin =$[[2.computed]]}}

That's great.  Thanks very much.  I appreciate the help, and the link so that I can get smarter on this stuff.