title: Error with arithmetic calculation
body: <p>I'm trying to calculate 2 retrieved values from <code>NSMutableArray</code> but there was error during runtime pointing to the way the arithmetic calculation was done.</p>
  
  <p>The code that inserts the value:</p>
  
  <pre><code>NSString *lastEx = @"None";
  int lastScore = 0;
  int tries = 0;
  int total_score = 0;
  int avg = 0;
  int credit = 100;
  
  [data addObject:lastEx];
  [data addObject:[NSNumber numberWithInt:lastScore]];
  [data addObject:[NSNumber numberWithInt:tries]];
  [data addObject:[NSNumber numberWithInt:total_score]];
  [data addObject:[NSNumber numberWithInt:avg]];
  [data addObject:[NSNumber numberWithInt:credit]];
  </code></pre>
  
  <p>Code to retrieve:</p>
  
  <pre><code>NSMutableArray *savedStock = [[NSMutableArray alloc] initWithContentsOfFile:path];
  
  previousExercise.text = [savedStock objectAtIndex:0];
  
  NSString *lastScoring = [NSString stringWithFormat:@"%d", [[savedStock objectAtIndex:1] intValue]];
  previousScore.text = lastScoring;
  
  NSString *totalTries = [NSString stringWithFormat:@"%d", [[savedStock objectAtIndex:2] intValue]];
  attempts.text = totalTries;
  
  NSString *average = [NSString stringWithFormat:@"%d", [[savedStock objectAtIndex:4] intValue]];
  avgScore.text = average;
  
  int totalScore = [[savedStock objectAtIndex:3] intValue];
  int numberOfTries = [[savedStock objectAtIndex:2] intValue];
  int avg;
  
  avg = ((totalScore / numberOfTries) * 100);
  
  NSString *rem_credit = [NSString stringWithFormat:@"%d", [[savedStock objectAtIndex:5] intValue]];
  credits.text = rem_credit;
  </code></pre>
  
  <p>Error is the calculation of  => <code>avg = ((totalScore / numberOfTries) * 100);</code></p>
  
  <p>Thanx in advance...</p>