The V.P.A.M. brand was first used in 1994 when the fx-991S and other scientific calculators from the "S" series were released in Japan. In 1998, the Casio fx-991W model used a two-tier (multi-line) display and the system was termed as S-V.P.A.M. (Super V.P.A.M.).

相比较前代fx-991ES PLUS升级不少，屏幕分辨率提升了近4倍，增加了中文显示和图形化的菜单页。 2019年10月新增蓝色、粉色、灰白色三种配色，这是同系列中别的型号所不具备的。

Manuals and User Guides for CASIO V.P.A.M. fx-991s Calculator. We have 1 CASIO V.P.A.M. fx-991s Calculator manual available for free PDF download: User Manual

fx-991CN X是fx-991ES PLUS的全面升级版，前者是目前中国官方在售的旗舰函数式计算器（无存储无编程无图像），可用在很多考试。 以下列出CN X新增的主要功能，是个人总结，可能有遗漏和差错。

fx-991MS. My GShock. Favorite. Find a Store Features. Fraction calculations Combination and permutation Statistics (STAT-data editor, Standard deviation, Regression analysis) 9 variable memories Comes with slide-on hard case. fx-82MS/85MS/350MS functions, in addition to:

Introduces the excellent features of the ES PLUS series 2nd edition. 1 Design Simple and easy to use. Optimal education tools realized through a design that emphasizes comfort in the hand, legibility, and usability through the pursuit of simplicity. The keys have been made rectangular, making them easier to press.

MS series calculators come with Scientific calculation, statistical calculation, differential*, and integration* functions. Exponent notation is the same as the notation in textbooks. Two-line display lets you view the expression and its result at the same time.

Generate QR codes of equations input into the calculator by a simple operation. Graphs and other graphics can be displayed on smartphone or tablet screens. Useful for learning statistics. Up to 5 columns × 45 rows (maximum of 170 data items) Perform calculations with matrices of up to 4 rows and 4 columns.