DOCUMENT();

loadMacros("PGstandard.pl","MathObjects.pl","PGML.pl","PGcourse.pl",);

Context("LimitedNumeric");

TEXT(beginproblem());
BEGIN_PGML
Enter a number: [___]
END_PGML

ANS(Real(-1)->cmp(checker => 
    sub{
       my ($correct,$student,$ansHash) = @_;
       $student_ans=$student;
       return 1; 
     }
));

$student_ans=$student_ans+1;

BEGIN_PGML
Add 1 to your previous answer: [___]{$student_ans}
END_PGML




ENDDOCUMENT();