You do know that when you click on an amount on a line that is not a number you have input and it has the little magnifying glass symbol, that you can click on it and it will take you back to the form that number came from.  and keep doing that til you reach the limitation form.  

Also, if you are at a line, and click on it, and the magnifying glass doesn't appear, you can right click your mouse, and find the last two options of that right click (cross reference, etc), they will normally  lead you to those calculations.