% Count grades example

% Initialize data:   
  highGrade = 100;                   % highest possible grade
  lowGrade  = highGrade-highGrade ;  % lowest possible grade
  goodGrade = .90*highGrade;         % good grade criteria
  count     = 0;                     % count of VALID grades so far

% Prompt for first grade:
  grade = input('Enter a grade: ');
   
% Report good grades and count all valid grades:
  while grade >= lowGrade & grade <= highGrade

    % Increment count of valid grades:
      count = count + 1;

    % Report if grade is good:
      if grade > goodGrade 
	disp('That is a good grade!');
      end

    % Get next grade:
      grade = input('Enter a grade: ');
      
  end
  
% Report the number of valid grades entered:
  if count==0
    disp('No valid grades entered!');
  elseif count==1;
    disp(['You entered ',num2str(count),' grade.']);
  else
    disp(['You entered ',num2str(count),' grades.']);
  end