At whatever time I twist on my TI-83 there are a number of parts in the screen that would not turn on. For illustration, if I put in 4+4, the reply comes out in the right side as 4. But there is a perpendicular line that blanks out that line. So the center of the 4 is missing and there is a straight line so I cannot even tell what that numeral is. Be able to somebody assist me I necessitate good calculator software. Where can I get it.
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