Most homework problems will specify  explicit limits on
the length of the answer, e.g., 4 lines, 2 paragraphs, etc.
Answers that appreciably exceed the limit will lose 
points.
<ul> 
<li> "Appreciably" means we won't quibble over minutia, and you shouldn't 
waste time
counting words or lines. 
<li> For a line limit, don't switch to
a small type font! 
<li> For a paragraph limit,
define a paragraph as roughly 4 sentences.
</ul>
The length limit will usually be much shorter than the length of a
completely detailed solution. To meet the limit restriction you must
omit inessential details, and concentrate on the most important
points.
 (A simple figure will not count towards the limit.)
<p>
The purpose of this line limit policy is twofold: 
<ol type="a">
<li> It forces you to 
crystallize your 
thoughts. It forces you to make the judgment of what is important and 
what is not. Both of these are good skills. 

<li> It makes the grading 
easier!
</ol>

<p>
<i>
``This letter would not be so long had I but the time to make it
shorter.''
</i>
-- Pascal

<p>
(Note: The heuristic I usually follow in setting the length limit is to
take the length of my solution and enlarge it by a small but significant 
factor. This allows for my deliberate succinctness, or someone doing it a 
different 
way, etc. "Small but significant factor" is roughly 4/3 or 3/2.)