Casio fx-991EX

Casio fx-991EX is a scientific calculator made by Casio. It has 552 functions and 12 modes.

Casio fx-991EX

Manufacturer	Casio
Dimensions	11.1 millimetres (0.44 in) thick
Mass	90 grams (3.2 oz)
CPU	25 MHz single-core
Memory	64K
Storage	32K (1.7K available for spreadsheet)
Battery	1 x LR44, solar, DC 1.5 V
Display	2.6 inches (6.6 cm) (2.4 inches (6.1 cm) viewable) 192x62 px, 86 ppi

Modes

1: Calculate

This mode allows you for basic calculations.

2: Complex

This mode allows you for complex calculations.

3: Base-N

This mode allows you for calculations in base 2, 8, 10 or 16.

4: Matrix

This mode allows you for matrices up to 4x4.

5: Vector

This mode allows you for vector calculations.

6: Statistics

This mode allows you for statistics.

Type	Max rows
x	160
x, Freq	80
x, y	80
x, y, Freq	53

7: Distribution

This mode allows you for distribution calculations.

8: Spreadsheet

This mode allows you for spreadsheets (up to 45 rows, 5 columns).

9: Table

This mode allows you for listing calculations up to 45 (f(x)) or 30 (f(x)) and g(x)) rows.

A: Equation/Func

This mode allows you for simulatmous equations and polynomials.

B: Inequality

This mode allows you for inequality polynomials.

C: Ratio 

This mode allows you for rational calculations.