Casio FX-991ES PLUS เครื่องคิดเลขวิทยาศาสตร์คาสิโอ คาสิโอ เครื่องคิดเลข
Natural textbook display shows expressions and results exactly as they appear in the textbookOver 418 functions including fractions statistics complex number calculations base arithmetic linear regression standard deviation computer science and polar-rectangular conversionsMulti-replay function allows you to backtrack step-by-step through calculations where you can edit expressions and recalculate answersBuilt-in batteryThe Plus version is an upgraded version with the same features but with better quality and more durability