Casio fx-991ZA PLUS II User Manual

Important!
• A Math ERROR will occur if you perform a calculation while 0 is input for a coefficient.
Changing the Ratio Expression Type
Re-enter the RATIO Mode and select the ratio expression type you want
from the menu that appears. Changing the ratio expression type causes
the values of all Coefficient Editor coefficients to change to zero.
RATIO Mode Calculation Example
Example 1: To calculate X in the ratio 1 : 2 = X : 10
(RATIO) (a:b=X:d)
1 2 10
Example 2: To calculate X in the ratio 1 : 2 = 10 : X
(RATIO)
(a:b=c:X)
1 2 10
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Casio fx-991ZA PLUS II Specifications

General

Type	Scientific Calculator
Number of Functions	552
Equation Solver	Yes
Matrix Calculations	Yes
Complex Number Calculations	Yes
Integration	Yes
Differentiation	Yes
Memory	9 variables
Weight	95 g
Protective Case	Yes
Display	Natural Textbook Display
Power Source	Solar and Battery