Basic Calculations - Casio fx-991ZA Plus User Manual

While Linear Display is selected, each press of f will toggle the currently
displayed calculation result between its decimal form and fraction form.
1 ÷ 5 = 0.2 = 1
1 / 5 =
1 – 4 4 = 1
5 5
1 - 4 ' 5 =
Important: • Depending on the type of calculation result that is on the display
when you press the f key, the conversion process may take some time to
perform. • With certain calculation results, pressing the f key will not convert
the displayed value. • You cannot switch from decimal form to mixed fraction
form if the total number of digits used in the mixed fraction (including integer,
numerator, denominator, and separator symbols) is greater than 10.
Note: With Natural Display (MathO), pressing 1= instead of =
after inputting a calculation will display the calculation result in decimal
form. Pressing f after that will switch to the fraction form or π form of the
calculation result. The ' form of the result will not appear in this case.

Basic Calculations

Fraction Calculations
Note that the input method for fractions is different, depending upon whether
you are using Natural Display or Linear Display.
2 + 1 = 7
3 2
1 = 1
4 − 3
2
Note: • Mixing fractions and decimal values in a calculation while Linear
Display is selected will cause the result to be displayed as a decimal value.
• Fractions in calculation results are displayed after being reduced to their
lowest terms.
To switch a calculation result between improper fraction and mixed
fraction form: Perform the following key operation: 1f( < )
To switch a calculation result between fraction and decimal form:
Press f.
Percent Calculations
Inputting a value and pressing 1((%) causes the input value to become
a percent.
150 × 20% = 30
b
5
b
= 0.2
5
B
6
or
b
B
4 -1'(() 3 e 1 c 2 =
2
b
1
2 ' 3 e+ 1 ' 2 =
' 2 c 3 e+' 1 c 2 =
2 ' 3 + 1 ' 2 =
4 - 3 ' 1 ' 2 =
150 * 20 1((%)=
EN-11
f
0.2
f
5
{
1 5
{
0.2
7
6
7
6
7 6
{
1
2
1 2
{
30