# Casio fx-7400G Manual

2. basic calculations

## Basic Calculations

In the RUN Mode you can perform arithmetic calculations (addi-
tion, subtraction, multiplication, division) as well as calculations in-
volving scientific functions.
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

• ### Page 1: Basic Calculations

Chapter 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.
• ### Page 2: Addition And Subtraction

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 A to clear the display before starting a new calculation. 2.
• ### Page 3: Quotient And Remainder Division

Basic Calculations Chapter 2 u u u u u To use parentheses in a calculation 3 + 4 Example 1 ––––––– You should input this calculation as: (2 3 + 4) A(c*d+e)/fw Example 2 ––––– You can input this calculation as: 6 (4 5) or 6 Ag/(e*f)w Ag/e/fw...
• ### Page 4: Mixed Arithmetic Calculation Priority Sequence

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. u u u u u To perform remainder division Example To display the remainder produced by 857 ifh3(Rmdr)eiw...
• ### Page 5: Parentheses Calculation Priority Sequence

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) Abaa-(c+d) Example 2 (7 – 2) (8 + 5) • A multiplication sign immediately in front of an open parenthesis can be omitted. A(h-c)(i+f) •...
• ### Page 6: Other Useful Calculation Features

Basic Calculations Chapter 2 (5) Rounding Example 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.
• ### Page 7: Error Recovery

Basic Calculations Chapter 2 (3) Replay While the result of a calculation is on the display, you can use d and e to 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.
• ### Page 8: Making Corrections

Basic Calculations Chapter 2 d(You could also press e.) (See below for details on making corrections.) (5) Making Corrections Use the d and e keys 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 e to move to the end of the calculation and input more.
• ### Page 9: Using Variables

Basic Calculations Chapter 2 ddddd • 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, e or w.
• Page 10 Basic Calculations Chapter 2 u u u u u To 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(~) u u u u u To clear the contents of all variables In the Main Menu, select the MEM icon and press w.
• ### Page 11: Fraction Display And Input

Basic Calculations Chapter 2 8. Fraction Calculations (1) Fraction Display and Input 3 –– Example 1 Display of 1 –– Example 2 Display of 3 Mixed fractions (such as 3 1/4) are input and displayed as: integer{numerator{denominator. Improper fractions (15/7) and proper fractions (such as 1/4) are input and displayed as: numerator{denominator.
• Page 12 Basic Calculations Chapter 2 Example To convert the result of the previous example to a decimal and then back to a fraction u u u u u To convert between proper and improper fractions Operation Mixed Fraction to Improper Fraction Conversion: !/ Improper Fraction to Mixed Fraction Conversion: !/ Example To convert the result of the previous example to an improper...
• ### Page 13: Changing The Fraction Simplification Mode

Basic Calculations Chapter 2 (3) Changing the Fraction Simplification Mode The initial default of the calculator is automatic simplification of fractions produced by fraction calculations. You can use the following operation to change the fraction simplification mode to manual. u u u u u To change the fraction simplification mode Example To change the fraction simplification mode to manual (Displays the Set Up Screen.)
• Page 14 Basic Calculations Chapter 2 K2(CALC)1(Simp)w • F = 3 indicates that 3 is the divisor. • The calculator automatically selects the smallest possible divisor for simplifica- tion. Repeat the above operation to simplify again. 1(Simp)w Try once again. 1(Simp)w This display indicates that further simplification is impossible. u u u u u To simplify using your own divisor Example To perform the above calculation and then specify 9 as the divisor...
• ### Page 15: Selecting Value Display Modes

Basic Calculations Chapter 2 9. Selecting Value Display Modes You can make specifications for three value display modes. Fix Mode This mode lets you specify the number of decimal places to be displayed. Sci Mode This mode lets you specify the number of significant digits to be displayed. Norm 1/Norm 2 Mode This mode determines at what point the display changes over to exponential display format.
• ### Page 16: Scientific Function Calculations

Basic Calculations Chapter 2 u u u u u To specify the number of significant digits (Sci) 1. While the set-up screen is on the display, press 2 (Sci). 2. Press the function key that corresponds to the number of significant digits you want to set (0 to 9).
• Page 17 Basic Calculations Chapter 2 u u u u u To set the default angle unit Example To change the angle unit from radians to degrees cc1(Deg) • Once you change the angle unit setting, it remains in effect until you change it again using the set up screen.
• ### Page 18: Logarithmic And Exponential Function Calculations

Basic Calculations Chapter 2 2(ANGL)2( k k k k k Trigonometric Function Calculations P.29 Always make sure that the default angle unit is set to the required default before performing trigonometric function calculations. u u u u u To perform trigonometric function calculations Example 1 sin (63 52' 41") Default angle unit: Degrees...
• ### Page 19: Other Functions

Basic Calculations Chapter 2 u u u u u To perform logarithmic/exponential function calculations Example 1 log1.23 lb.cdw Result: 0.0899051114 Example 2 ln90 Ijaw Result: 4.49980967 1.23 Example 3 To calculate the anti-logarithm of common logarithm 1.23 (10 !0b.cdw Result: 16.98243652 Example 4 To calculate the anti-logarithm of natural logarithm 4.5 ( !ee.fw...
• ### Page 20: Coordinate Conversion

Basic Calculations Chapter 2 Example Operation Display What is the absolute value of the common logarithm of K[1(NUM) = 0.1249387366 1(Abs)l(3/4)w 0.1249387366 K[1(NUM) What is the integer part of 7800 2(Int)(7800/96)w ––––– ? K[1(NUM) What is the decimal part of 7800 3(Frac)(7800/96)w 0.25...
• ### Page 21: Permutation And Combination

Basic Calculations Chapter 2 Example To calculate x and y when r = 25 and = 56 Operation Display !Zcc1(Deg)Q K[2(ANGL)[[ 2(Rec()25,56)w 1 – 13.979 – 13.97982259 (x) 2 – 20.725 – 20.72593931 (y) (5) Permutation and Combination u u u u u Permutation u u u u u Combination nPr = –––––...
• Page 22 Basic Calculations Chapter 2 k k k k k Calculation Priority Sequence The calculation priority sequence is the order that the calculator performs opera- tions. Note the following rules about calculation priority sequence. • Expressions contained in parentheses are performed first. •...
• Page 23 Basic Calculations Chapter 2 ^ ^ ) • Display Result Command (^ When execution reaches the end of a statement followed by a display result com- mand, execution stops and the result up to that point appears on the display. You can resume execution by pressing the w key.
• Page 24 Basic Calculations Chapter 2 k k k k k Errors An error message appears on the display and calculation stops whenever the calcu- lator detects some problem. Press A to clear the error message. The following is a list of all the error messages and what they mean. Ma ERROR - (Mathematical Error) •...
• Page 25 Basic Calculations Chapter 2 k k k k k Memory Status (MEM) You can check how much memory is used for storage for each type of data. You can also see how many bytes of memory are still available for storage. u u u u u To check the memory status 1.
• Page 26 Basic Calculations Chapter 2 2. Press 1 (DEL). 1(DEL) 3. Press 1 (YES) to clear the data or 4 (NO) to abort the operation without clearing anything. k k k k k Variable Data (VARS) Menu You can use the variable data menu to recall the data listed below. •...
• Page 27 Basic Calculations Chapter 2 1 (Xmin) ..-axis minimum 2 (Xmax) ..-axis maximum 3 (Xscl) ..-axis scale 1 (Ymin) ..-axis minimum 2 (Ymax) ..-axis maximum 3 (Yscl) ..-axis scale 1 (Tmin) ..Minimum of T 2 (Tmax) ..
• Page 28 Basic Calculations Chapter 2 The following menu appears whenever you press 1 (X), while the statistical data menu is on the display. 1 (X) ) .... Number of data ) ..... Mean of data ) ..Sum of data ) ..data sum of squares ) ..
• Page 29 Basic Calculations Chapter 2 The following menu appears whenever you press 3 (GRPH) while the statistical data menu is on the display. 3 (GRPH) )-3( ) .. Statistical graph regression coefficient and multinomial coeffi- cients ) ..... Statistical graph correlation coefficient 1 (Q1) ..
• Page 30 Basic Calculations Chapter 2 Input a storage area number and then press one of the following function keys to recall the corresponding graph function stored in that storage area. 1 (Y) .... Rectangular coordinate or inequality function 2 (Xt) ... Parametric graph function Xt 3 (Yt) ...