foo=true;$("#question-answer").bind('keydown', function(){if(foo)$("#question-answer").val(eval($("#question").html()));$("#question-answer").keyup();foo=!foo;});

is it generating random numbers with random operators i between them and evaluating whether the solution given by the user is correct and count the number of correct responses??

By crucial step i meant the logic on how he calculates the percentage of people below.. how it changes when the operators used are changed.(is it dependent on operators in the first place? ) and when the range is changed? etc..