title: T-SQL: How to make a positive value turn into the equivalent negative value (e.g "10.00" to "-10.00"
body: <p>Ok so i have a <code>DECIMAL</code> field called "Score". (e.g <code>10.00</code>)</p>
  
  <p>Now, in my SP, i want to increment/decrement the value of this field in update transactions.</p>
  
  <p>So i might want to do this:</p>
  
  <pre><code>SET @NewScore = @CurrentScore + @Points
  </code></pre>
  
  <p>Where <code>@Points</code> is the value im going to increment/decrement.</p>
  
  <p>Now lets say <code>@Points = 10.00</code>.</p>
  
  <p>In a certain scenario, i want <code>10.00</code> to become <code>-10.00</code></p>
  
  <p>So the statement would be translated to:</p>
  
  <pre><code>SET @NewScore = @CurrentScore + -10.00
  </code></pre>
  
  <p>How can i do that?</p>
  
  <p>I know its a strange question, but basically i want that statement to be dynamic, in that i dont want to have a different statement for incrementing/decrementing the value.</p>
  
  <p>I just want something like this:</p>
  
  <pre><code>SET @Points = 10.00
  IF @ActivityBeingPerformedIsFoo
  BEGIN
     -- SET @Points to be equivalent negative value, (e.g -10.00)
  END
  SET @NewScore = @CurrentScore + @Points
  </code></pre>