+ 0 Votes More Info? Mehul Bhai March 3, 2013 at 9:25pm PST You have not given information about the make and model of the calculator. Even then I will try to help you. It has to be battery only but if it doesnot solve your problem then you have to take it to a repair store. + 0 Votes Reponse To Answer Slayer_ March 5, 2013 at 6:24am PST Because the Chinese child that made it wasn't whipped enough that day. + 1 Votes Batteries RSmiedy March 3, 2013 at 10:31pm PST It may be the batteries or the back light display. If it is not the batteries than buy a new one. + 1 Votes Regarding calculator rahulwalame March 4, 2013 at 3:01am PST but why such things happened I bought it just 15 days ago.