Hit the #1 key get an error / z out and shows $6900 on xe-a102?

Each time I hit the number 1 key I get an error. When I z out the machine in the 1 key posting is $6,398.44. I tried removing batteries, turning off the machine for several minunites, then re-z the machine and again the same amount showed in the 1 key positon. HOW CAN I CLEAR THIS AMOUNT FROM THE 1 KEY POSITION AND be able to use the key during normal transactions without getting an error (e) and beep?