Keep a straight edge wherever you bring your calculator! Made in the USA, invented by a high school math teacher Featuring a 6 inch side ruler, a 6 cm top ruler, an XY axis template that will cut down time graphing axes and 12 Math functions that are important for any mathematician (middle school to college). Supmay Hard Case for Texas Instruments TI-84 Plus CE/TI-84 TI Hard Slider Case Back Cover - Compatible with TI-84 Plus, TI-84 Plus C, TI-89 Titanium Graphing Calculator Add to cart Best Seller Thank you for shopping EZ Graphing! EZ graphing slide cases are the only patented slide cover on the market that offers functionality to a calculator cover. Every slide case is made in the USA! Please purchase our product with this in min. Not only can the XY axis template help you graph, but it can draw perfect rectangles, 3-4-5 right triangles, isosceles triangles, parallel lines and much more. TI-84 Plus CE EZ Spot Yellow Slide Cases - Pack of 10 Great for geometry, algebra, precalculus and calculus classes. Graphing Calculator Hard Case CATI Hard Slider Case Back Cover For TI-84 Plus, TI-84 Plus C Calculator Case With Ruler