Casio fx-7400G User manual

Basic Calculations
In the RUN Mode you can perform arithmetic calculations (addi-
tion, subtraction, multiplication, division) as well as calculations in-
volving scientific functions.
1. Addition and Subtraction
2. Multiplication
3. Division
4. Quotient and Remainder Division
5. Mixed Calculations
6. Other Useful Calculation Features
7. Using Variables
8. Fraction Calculations
9. Selecting Value Display Modes
10. Scientific Function Calculations
Chapter 2

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Basic Calculations Chapter 2
1. Addition and Subtraction
Example 6.72 + 9.08
g.hc+j.aiw
You can input the operation just as it is written. This capability is called “true alge-
braic logic.”
Be sure to press Ato clear the display before starting a new calculation.
2. Multiplication
Example 3.71 ×4.27
Ad.hb*
e.chw
• The range of this calculator is –9.99999999 ×1099 to +9.99999999 ×1099.
3. Division
Example 64 ÷4
Age/ew
Parentheses also come in handy when performing division. For full details on using
parentheses, see “Parentheses Calculation Priority Sequence”.
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Basic Calculations Chapter 2
uu
uu
uTo use parentheses in a calculation
2 ×3 + 4
Example 1 –––––––
5
You should input this calculation as: (2 ×3 + 4) ÷5
A(c*d+e)/fw
6
Example 2 –––––
4×5
You can input this calculation as: 6 ÷(4 ×5) or 6 ÷4 ÷5.
Ag/(e*f)w
Ag/e/fw
4. Quotient and Remainder Division
This calculator can produce either the quotient or the quotient and remainder of
division operations involving two integers. Use Kto display the Option Menu for
the function key menu you need to perform quotient and remainder division.
Operation
Use the RUN Mode for quotient and remainder division.
Quotient Division .......<integer>K2(CALC)2(Int÷)<integer>w
Reminder Division .....<integer>K2(CALC)3(Rmdr)<integer>w
uu
uu
uTo perform quotient division
Example To display the quotient produced by 61 ÷7
AgbK2(CALC)
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Basic Calculations Chapter 2
2(Int÷)hw
• Remember that you can use only integers in quotient division operations. You
cannot use expressions such as 2 or sin60 because their results have a decimal
part.
uu
uu
uTo perform remainder division
Example To display the remainder produced by 857 ÷48
ifh3(Rmdr)eiw
Press Qto clear the Option Menu after you finish your remainder and quotient
calculations.
• Remember that you can use only integers in remainder division operations. You
cannot use expressions such as 2 or sin60 because their results have a decimal
part.
• Quotient and remainder division can also be used with lists to divide a multiple
integers by each other in a single operation.
5. Mixed Calculations
(1) Mixed Arithmetic Calculation Priority Sequence
For mixed arithmetic calculations, the calculator automatically performs multiplica-
tion and division before addition and subtraction.
Example 1 3 + 5 ×6
Ad+f*gw
Example 2 7 ×8 – 4 ×5
Ah*i-e*fw
1234
1234
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Basic Calculations Chapter 2
(2) Parentheses Calculation Priority Sequence
Expressions enclosed inside parentheses are always given priority in a calculation.
Example 1 100 – (2 + 3) ×4
Abaa-(c+d)
*ew
Example 2 (7 – 2) ×(8 + 5)
• Amultiplication sign immediately in front of an open parenthesis can be omitted.
A(h-c)(i+f)
w
• Any closing parentheses at the end of a calculation can be omitted, no matter
how many there are.
Parenthesesarealwaysclosedintheoperationexamplespresentedinthismanual.
(3) Negative Values
Use the -key to input negative values.
Example 56 ×(–12) ÷(–2.5)
Afg*-bc/
-c.fw
(4) Exponential Expressions
Use the Ekey to input exponents.
Example (4.5 ×1075) ×(–2.3 ×10–79)
Ae.fEhf*-c.d
E-hjw
The above shows what would appear when the exponential display range is set to
Norm 1. It stands for –1.035 ×10–3, which is –0.001035.
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Basic Calculations Chapter 2
(5) Rounding
Example 74 ÷3
Ahe/dw
The actual result of the above calculation is 24.66666666… (and so on to infinity),
which the calculator rounds off. The calculator’s internal capacity is 15 digits for the
values it uses for calculations, which avoids accuracy problems with consecutive
operations that use the result of the previous operation.
6. Other Useful Calculation Features
(1) Answer Memory (Ans)
Calculation results are automatically stored in the Answer Memory, which means
you can recall the results of the last calculation you performed at any time.
uu
uu
uTo recall Answer Memory contents
Press !and then K(which is the shifted function of the -key).
This operation is represented as !Kthroughout this manual.
Example To perform 3.56 + 8.41 and then divide 65.38 by the result
Ad.fg+i.ebw
gf.di/!Kw
(2) Consecutive Calculations
If the result of the last calculation is the first term of the next calculation, you can use
the result as it is on the display without recallingAnswer Memory contents.
uu
uu
uTo perform a consecutive calculation
Example To perform 0.57 ×0.27, and then add 4.9672 to the results
Aa.fh*a.chw
+e.jghcw

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Basic Calculations Chapter 2
(3) Replay
While the result of a calculation is on the display, you can usedand eto move the
cursor to any position within the expression used to produce the result. This means
you can back up and correct mistakes without having to input the entire calculation.
You can also recall past calculations you have already cleared by pressing A.
Operation
The first press of edisplays the cursor at the beginning of the expression, while
ddisplays the cursor at the end. Once the cursor is displayed, use eto move it
right and dto move it left.
uu
uu
uTo use Replay to change an expression
Example To calculate 4.12 ×6.4 and then change the calculation to 4.12 ×7.1
Ae.bc*g.ew
d
dddh.bw
Multi-Replay
Pressing Aand then for csequentially recalls and displays past calculations.
(4) Error Recovery
Whenever an error message appears on the display, press dor eto re-display
the expression with the cursor located just past the part of the expression that caused
the error. You can then move the cursor and make necessary corrections before
executing the calculation again.
uu
uu
uTo correct an expression that causes an error
Example To recover from the error generated by performing 148 ÷0. ×3.37
instead of 148 ÷0.3 ×3.37
Abei/a.
*d.dhw

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Basic Calculations Chapter 2
d(You could also press e.)
![d
(See below for details on making
corrections.)
w
(5) Making Corrections
Use the dand ekeys to move the cursor to the position you want to change, and
then perform one of the operations described below. After you edit the calculation,
you can execute it by pressing w, or use eto move to the end of the calculation
and input more.
uu
uu
uTo change a step
Example To change cos60 to sin60
cga
ddd
s
uu
uu
uTo delete a step
Example To change 369 × × 2 to 369 ×2
dgj**c
ddD
uu
uu
uTo insert a step
Example To change 2.362to sin2.362
c.dgx

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Basic Calculations Chapter 2
ddddd
![
s
• When you press ![a space is indicated by the symbol ‘‘t’’. The next func-
tion or value you input is inserted at the location of ‘‘t’’. To abort the insert opera-
tion without inputting anything, move the cursor, press ![again, or press
d, eor w.
7. Using Variables
A total of 26 variables, named A through Z, are available for assignment of numeric
values. Variable contents are retained even when you turn the calculator off. Note
that when you assign a value to a variable, the calculator assigns its 15-digit internal
value.
uu
uu
uTo assign a value to a variable
Operation
<value or expression>aa<variable name: Ato Z>
Example 1 To assign 1024 to variable A
AbaceaaAw
Example 2 To display the contents of variableA
AaAw
Example 3 To clear the contents of variable A
To clear a variable, simply assign 0 to it.
AaaaAw

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Basic Calculations Chapter 2
uu
uu
uTo assign the same value to more than one variable
Operation
<value or expression>aa<start variable name>a3(~)a<end variable
name>w
Example To assign the result of 2 to variables A, B, C, D, and E
A!9caaAa3(~)
aEw
uu
uu
uTo clear the contents of all variables
In the Main Menu, select the MEM icon and press w.
Select Memory Usage.
w
Press cto scroll the display until “Alpha” is highlighted.
ccccccc
1(DEL)
Press 1(YES) to clear all variables or 4(NO) to abort the clear operation without
clearing anything.
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1234