Casio fx-991CW: Input Output Formats

Casio fx-991CW: Input Output Formats

The Four Formats

There are four input/output formats that the Casio fx-991CW has. With each mode, I will show three example problems and the default format the of the output. If you always want Decimal approximations, I would suggest setting the calculator to either MathI/DecimalO or LineI/DecimalO settings.

To set the input/output:

1. Press [ SETTINGS ].

2. Select Calc Settings and press either [ EXE ], [ OK ], or [ → ].

3. Select Input/Output and press either [ EXE ], [ OK ], or [ → ].

4. Select a format and press either [ EXE ] or [ OK ]. The circle next to the mode selected will be filled.

5. To quickly return the home screen, press [ AC ].

MathI/MathO: Math Input/Math Output

Expressions are entered and displayed as written in textbook fashion. The fx-991CW returns results in exact form whenever possible in terms of π, square roots, and fractions. To get decimal approximations, press [ FORMAT ] and select Decimal.

Default (Radians Mode):

4 / 5 + 3 / 8 returns 47 / 40

√440 returns 2 × √110

cos^-1(0.5) returns 1 / 3 × π

MathI/DecimalO: Math Input/Decimal Ouptut

Expressions are entered and displayed as written in textbook fashion. However, in this mode, the fx-991CW always returns the results as decimal expressions. You can still ask for exact answers, whenever possible, by pressing [ FORMAT ] and selecting Standard.

Default (Radians Mode):

4 / 5 + 3 / 8 returns 1.175

√440 returns 20.97617696

cos^-1(0.5) returns 1.04719551

LineI/LineO: Line Input/Line Output

Expressions are entered in one-line format, similar to classic computers and calculators. Results, when possible and when fractions are used, are returned using fractions. Otherwise, all other results are returned in decimal approximation. To get decimal approximations on fractions, press [ FORMAT ] and select Decimal.

Default (Radians Mode):

4 / 5 + 3 / 8 returns 47 / 40

√440 returns 20.97617696

cos^-1(0.5) returns 1.04719551

LineI/DecimalO: Line Input/Decimal Output

Expressions are entered in one-line format, similar to classic computers and calculators. However, in this mode, the fx-991CW always returns the results as decimal expressions. To see if the approximation can be converted to fractions (within the limitation of the calculator) press [ FORMAT ] and select Standard.

Default (Radians Mode):

4 / 5 + 3 / 8 returns 1.175

√440 returns 20.97617696

cos^-1(0.5) returns 1.04719551

I hope you find this helpful. Until next time,

Eddie

All original content copyright, © 2011-2024. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.

Retro Review: Texas Instruments Galaxy 40sx

Retro Review: Texas Instruments Galaxy 40sx

Quick Facts

Model:  Texas Instruments Galaxy 40sx

Company:  Texas Instruments

Years:  1991  (early 1990s)

Type:  Scientific

Power:  Solar Power

Display:  1 line, 10 digits

Memory Register:  1

Operating System:  Algebraic (prefix, AOS)

Features

The TI-Galaxy 40 sx is a landscape, scientific calculator which has the basic scientific calculator features plus several extras:

*  Trigonometry.  There are two angle modes: degrees and radians. 

*  1-variable statistics

*  Polar/Rectangular Conversion

*  Powers, Roots, Logarithms, Exponentials

*  Factorial of positive integers to 69

*  Scientific notation and cancellation of the scientific notation view mode

*  Two single-operation macros

The calculator is protected by a hard slide case, which slides on and off.  

The [ -x ] is the change sign key. 

The Galaxy 40 sx is the solar-powered version of the Galaxy 40 sx.  

Parenthesis

When the parenthesis keys [ ( ] and [ ) ] are pressed, the calculator keeps track of open parenthesis on the screen.   

For example:   (( 2 + 1.8 ) ÷ 3 )^3 ≈ 2.032296296

[ ( ]        [Screen:    (    One open level.]

[ ( ]        [Screen:   ( (   Two open levels.]

2 [ + ]

1.8 [ ) ]  [Screen:  ) flashes, then shows 3.8.  One open level left.]

[ ÷ ] 3 

[ ) ]         [Screen:  1.266666667]

[ 2nd ] (y^x)

3 [ = ]    [Screen:  2.032296296]

Fractions

The Galaxy 40sx has an emphasis on fractions:

[ |- ]:  Euclidean Division.    This function divides two integers and shows the quotient and remainder.

Example:

148 [ |- ] 39 [ = ] :    Q:  3   R : 31

Entering Fractions:

[ u ]:   Unit (whole number)

[ / ]:  Fraction key.  Enter the numerator, press [ / ], then enter the denominator.

Example:

Enter 5 4/9.   5 [ u ] 4 [ / ] 9 [ = ]:    5 u 4/9

[ F<>D ]:  Fraction/Decimal Conversion.  The algorithm is not perfect as if has a hard time converting many digits to fractions.   For example:  1.666666667 does not convert to 5/3.   0.142857143 does not convert to 1/7.  Your mileage may vary. 

[ F→A b/c ]:  Converts an improper fraction to a mixed fraction.  

Example:

427/19.   427 [ / ] 19 [ F→A b/c ]:  22 u 9/19

[ SIMP ]:  Simplify fractions.  When N/D→n/d appears on the left hand the screen, the displayed fraction can be simplified.  You can choose the factor or let the calculator choose the factor. 

To choose the factor, press [ SIMP ], enter a factor, then press [ = ].

To have the calculator choose the factor, press [ SIMP ], then press [ = ].

In either case, you can view the factor used by pressing [ 2nd ] [ SIMP ] (DIV).  To continue simplifying, press [ x<>y ] to get the fraction back on the screen.  

Example:  Let the calculator choose the factor.

24/88.  

[ SIMP ] [ = ]:   12/44.   [ 2nd ] [ SIMP ] (DIV):  2

[ x<>y ]

[ SIMP ] [ = ]:   6/22.   [ 2nd ] [ SIMP ] (DIV):  2

[ x<>y ]

[ SIMP ] [ = ]:   3/11.   [ 2nd ] [ SIMP ] (DIV):  2

A fraction is irreducible when N/D→n/d is no longer on the screen.

Memory Arithmetic

The Galaxy 40sx has one memory register.   

[ STO ]:  Store number into the memory register.

[ RCL ]:  Recall the number from the memory register.

[ SUM ]:  Adds the number to the memory register.  (STO+)

[ 2nd ] [ STO ] (EXC):  Exchanges the number in the memory with the contents of the memory register.  

Single-Operation Macros

The Galaxy 40sx has two single-operation macros: OP1 and OP2.   The operations can be stored are:

[ + ] n :  Addition

[ - ] n :  Subtraction

[ × ] n :  Multiplication

[ ÷ ] n : Division

[ y^x ] n : Power

[ ˣ√  ] n :  Roots (principal roots)

Storing each macro will also display any arithmetic operation, which is nice.  

Pressing [ 2nd ] (<OP1) or (<OP2) clears the macro.   

This allows for repeated calculations.

Example:  Square 4, 7, and 11.

[ AC/ON ] [ 2nd ] [ x^2 ] (y^x) [ OP1 ]

4 [ OP1 ]:   Display  1    16   (answer: 16,  1st step)

7 [ OP1 ]:   49  

11 [ OP1 ]:  121

Note:  When executing macros, there is a number on the left that indicates the number of times [ OP1 ] or [ OP2 ] has been pressed repeatedly, until 10 or more digits of the answer is displayed.   I find that potentially confusing.  

Final Thoughts 

I like the keyboard.   I wish the calculator had a full-simplification function as an option.   I would also love to see the SIMP key double as a prime factorization of an integer.   The parenthesis tracker and operation macros are nice.  

The calculator works best in full light and has some extra features above the basic scientific calculator.  

Source

Datamath.  "Texas Instruments Galaxy 40sx"  Last Updated December 5, 2001.  Retrieved August 14, 2023.  http://www.datamath.org/Sci/Galaxy/TI40_Galaxy.htm

The manual that can be downloaded is in Dutch.  

All original content copyright, © 2011-2023.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

Numworks Software Version 20 Now Available

 Numworks Software Version 20 Now Available 

Click here for details:

https://www.numworks.com/calculator/update/version-20/

Highlights:

*  Separate Finance and Distribution Applications

*  Pressing the divide key [ ÷ ] prior to number entry cycles between:  Ans divided by denominator, fraction, mixed fraction.  

*  Pressing the Home Key then the 0 key gets the shortcut to Settings

*  The new Elements app is available.  We can display each element by its family, s/p/d/f blocks, type of metals, molar mass, electronegativity, melting temperature, boiling temperature, and atomic radius.  Each attribute is shown separately.

* When a value is highlighted in any app, except in Python, pressing [ shift ] (sto→) will give you a prompt to store the amount in a variable.  As a reminder, variables can have more than one character.

*  In the Grapher app, points of interest (zeroes/roots, minima, maxima, points of inflection, etc.) will have black dots.

*  Also in the Grapher app, the ability to find integrals is added to the toolbox.

*  Inverse trig functions are now labeled as arcsin, arccos, and arctan.  

*  Degree and degree minute second templates are loaded from the Toolbox > Units and constants > Length and angle > Angle submenu.

* Additional information is added to angle, trigonometric, and vector calculations.  

* We can add and subtract percents directly.   

There seems to not be additions to the Python programming module (yet).

To update:  just sign in to your Numworks account.  Then connect your calculator, select Update under the Calculator and follow the prompts.  Easy as that!

Thank you, Numworks! 

Eddie

Casio fx-9750GIII: Decimal Expansion of a Fraction

Casio fx-9750GIII:  Decimal Expansion of a Fraction

Introduction - Happy New Year!

The program DEC21 finds a decimal expansion of a positive fraction.  This program is based on Barry Kissane's DECIMAL program from "Programming Your Calculator: Casio fx-7400G Plus" (see source below).  

Casio fx-9750GIII Program:  DEC21

244 bytes

"2022-11-22 EWS"

"FRACTION EXPANSION"

"NUM.(>0) "?→N

"DEN.(>0) "?→X

Int log (N/X)+1→T

ClrText

Locate 1,2,N

Locate 13,2,"÷"

Locate 1,3,X

Locate 13,3,"≈"

For 1→I To 21

If T=0

Then 

Locate I,5,"."

I+1→I

IfEnd

Int (N÷X)→D

10*(N-D×X)→N

Locate I,5,D

T-1→T

Next

Locate 18,1,"   "

Note:  the approximate symbol, ≈, is found in the CHAR menu.

Examples:

Example 1:

558/127

NUM:  558

DEN:  127

Result:

558 ÷

127 ≈

4.3937007874015748031

Example 2:

5/27

NUM: 5

DEN: 27

5  ÷

27  ≈

0.1851851851851851851

Here's to a great 2023!

Source

Kissane, Barry.  Programming Your Calculator: Casio fx-7400G Plus. Chatswood NSW, Australia, 2000. ISBN 0 9758302 0 3.   

Eddie

Remember, my regular posting schedule for January and February 2023 is on Saturdays only. 

All original content copyright, © 2011-2023.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

Review: Sharp EL-344RB

Review: Sharp EL-344RB

Quick Facts

Model: Elsi Mate EL-344R

Company: Sharp

Years: production began around 2015

Memory Register:  1 independent memory

Power:  Solar with with LR1130 backup battery

Screen:  LCD, 10 digits

Logic:  Chain

First, the Basics

The EL-344R is a basic four-function calculator including percent and square root.   The memory keys [ M+ ] and [ M- ] not only complete the calculation but execute the appropriate storage arithmetic function.  The [ R∙CM ] key acts the dual function recall/clear memory.

Fractions and Approximations

You can enter fractions by using the [ a-b/c ] key.   There is a two digit limit to the numerator and denominator.  

Results can be converted to fractions.  However, the denominators offered are limited to n/2, n/4, n/8, n/16, and n/32.   If an exact fraction cannot be found, an APP indicator will show with an up or down arrow to show if the result has been rounded up or down.   In any case, the exact decimal is kept for future calculations.

Conversions

The large feature for the EL-344R is the set of metric-U.S. conversions.   Conversions include (not an all-exhaustive list):

*  temperature (°F/°C)

*  length (in/cm, ft/m, yd/m mi/km)

*  area (in^2/cm^2, ft^2/m^2, yd^2/m^2, acre/ha etc.)

*  volume (in^3/cm^3, ft^3/m^3, US gal/L, etc.)

*  weight (oz/g)

There are 44 preset conversions.    You can use the [ >A ] and [ <B ] keys allow you to set a custom conversion rate and use it for conversion calculations.

The conversions are nice, quick, and easy, and gives regular calculator an extra useful feature.   

Verdict

I like the rich set that compliments the EL-344R.   To me, the selling point is the nice set of conversions.   The keys are easy to press and I love the clear screen with large digits.  Recommended.

Eddie

All original content copyright, © 2011-2021.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

Retro Review: Casio fx-55 Fraction Mate

 Retro Review: Casio fx-55 Fraction Mate

Quick Facts

Model: fx-55 Fraction Mate

Company: Casio

Years: probably the 1990s or early 2000s, predecessor to the fx-55 Plus* 

Memory Register:  1 independent memory

Battery:  Solar with battery back up (LR44)

Screen:  8 digits, 4 digit numerator, 4 digit denominator, function indicator (+, -, ×, ÷, ^), equals and parenthesis indicators 

Logic:  Algebraic

Comes with hard case and reference card  

In 2018, I reviewed the fx-55 Plus:  https://edspi31415.blogspot.com/2018/08/review-casio-fx-55-plus.html

Right now there are plenty of fx-55 (original keyboard) for sale on auction sites for eBay at really inexpensive prices, sometimes as low as about $2.00.

Target Audiences

*  Elementary and middle school students

*  Anyone who wants a few more functions than a regular four-function calculator, but not a scientific calculator

*  You want a calculator with an emphasis on fractions

Keyboard

The fx-55 Fraction Mate does not have a shift key.   Some of the keys are:

[ + ], [ - ], [ × ], [ ÷ ]:  Arithmetic keys

[ ( ], [ ) ]:  Parenthesis keys

[ x^y ]:  Power key with a caret indicator on the screen

[ 1/x ]:  Reciprocal

[ RAN# ]:  3 digit random number between 0 and 1

[ FIX ]:  Fix setting.  For float setting, press [ FIX ] [ . ]

[ RND ]:  Round number to fixed setting internally

[ 10^x ]:  Antilog function

[ X ←→ Y ]:  Switch operators

[ X ←→ M]:  Exchange number in the display with number in memory

[ % ]: Percent key, see below

[ > ]: Backspace key

[ a ], [ b/c ]:  Fraction entry keys

[ F ←→ D ]:  Fraction/decimal conversion

[ a b/c ←→ d/c ]:  Improper/proper fraction conversion

[ SIMP ]:  Fraction simplification key

[ ÷R ]:  Integer division, with quotient and remainder.  If both numbers are positive, then remainder acts as a modulo operator

[ √ ]: square root

[ x^2 ]: square function

Integer Division

Pressing [ ÷R ] will return both the quotient and remainder of a division calculation.  If both numbers are positive, then the remainder is the modulo.  

Example:  55 [ ÷R ] 12 returns 4 R 7.  Then 55 = 7 MOD 12.

Percent Key

To add % to n, press:

n [ × ] p [ % ] [ + ]

To subtract % from n, press:

n [ × ] p [ % ] [ - ]

Simplify Key

The [ SIMP ] key simplifies fractions when possible.   The factor used to simplify the fraction is briefly displayed.  All fractions on the fx-55 FRACTION MATE are simplified manually.

Example:   1450/2900 = 

1450 [ b/c ] 2900 [ = ]

Display:  = 1450/2900  Simp

The Simp indicator means the fraction can be simplified.

[ SIMP ]

2 brifely displays before 725/1450 Simp

Repeated presses of [ SIMP ]:

5,  145/290 Simp

5,  29/58  Simp

29,  1/2

Order of Operations

The fx-55 follows the order of operations.  This is great for students in algebra.  

Example: 

3 [ + ] 9 [ × ] 11 [ = ] returns 102     (multiplication/division first, then addition/subtraction) 

Verdict

I like the fx-55 Fraction Mate.  It has a lot of additional functions that beyond the traditional four-function calculator:  parenthesis, powers, reciprocal, fractions.  The display and the numbers are big.  I like how the arithmetic and power functions are displayed.   Worth the buy.

Casio Ledudu's page for fx-55, including the manual:  https://casio.ledudu.com/pockets.asp?type=1176&lg=eng

Eddie

All original content copyright, © 2011-2021.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

Review: Victor 940

 Review:  Victor 940

Just the Facts

Company:  Victor

Type:  Scientific - Algebraic

Display:  10 digits with 2 digit exponents

Power:  Solar with battery back up LR43 battery

Memory Registers: 8:  A, B, C, D, E, F, X, Y, M

Cost:  about $8 to $10

Website:  https://www.victortech.com/product/940

Features

*  Trigonometry, Exponential, Logarithms

*  Factorial, Combinations, Permutations

*  Algebraic Expression Evaluation with fractions

*  Memory Arithmetic with M+ and M-

*  Statistics

*  Regressions:  Linear, Logarithm, Exponential, Power, Inverse, Quadratic

*  Two Line Display:  the top line is for typing mathematical expressions, the bottom line is for displaying results.

Essentially, the Victor 940 is a clone of the Casio fx-300MS/fx-85WA.  Many calculators are OEM clones, two other examples include the Bazic 300 and Hewlett Packard HP 10s+.  

You can find more information about the Casio fx-300MS/fx-85WA here:  

http://edspi31415.blogspot.com/2019/01/retro-review-casio-fx-85wa.html

Keyboard

The Victor 940 has a white keyboard with sky blue and orange font.   What differs the Victor 940 are:

*  The display is nice and large compared to the rest.  

*  I like the colors on the keyboard and the contrast on the font.  It could be just personal preference.  

*  The placement of the [ ON ], [ MODE ], [ALPHA], and [SHIFT] keys are different:  with the [ ON ] and [ MODE ] keys on the left of the arrow keys and [ALPHA] and [SHIFT] keys on the right of the arrow keys.  

I am not a fan of the plastic cover case.  Removing the case the first time was difficult and will require force.  The case does not cover the entire calculator, leaving the top of the calculator is left uncovered.  The case does cover the screen, keys, and solar panels are covered.

Verdict

I like the big screen on the Victor 940.  Other than that, it is like the Casio fx-300MS: plenty of functions for a low price.  

Eddie

All original content copyright, © 2011-2021.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

Retro Review: Radio Shack EC-4018

 Retro Review:   Radio Shack EC-4018

HAPPY NEW YEAR!

Quick Facts:

Company:  Radio Shack

Model:  EC-4018

Equivalent of:  Casio fx-470

Type:  Scientific 

Years:  Late 1980's

Display:  10 digits

Batteries:  Solar

Memory Registers: 1

Keyboard

The keyboard of the EC-4018 is a folding landscape.    The top half has the screen and 18 gray keys (scientific) to the right side, and two solar panel strips to the left.  The bottom half has 15 large black keys (arithmetic).  I really like the large keys on this calculator.  The keys are really easy to press and operated, and they also have a nice feel to them.  

Features

*  Trigonometric functions, logarithms, powers, rots

*  Convert to and from degrees-minutes-seconds

*  Four base conversions:  binary, decimal, octal, hexadecimal

*  Boolean Algebra: AND, OR, XOR, NEG

*  Fractions, combinations, permutations, reciprocal, factorials of integers

Physical Constants

INV 1:  Speed of Light in a Vacuum: c =  299792458 m/s

INV 2:  Planck's Constant:  h = 6.626176 * 10^-34 J s 

INV 3:  Universal Gravitational Constant:  G = 6.672 * 10^-11 N m^2/kg^2

INV 4:  Elementary Charge:  e = 1.6021892 * 10^-19 C

INV 5:  Electron Rest Mass:  me = 9.109534 * 10^-31 kg

INV 6:  Atomic Mass Unit:  u = 1.6605655 * 10^-27 kg

INV 7:  Avogadro's Constant:  Na = 6.022045 * 10^23/mol

INV 8:  Boltzmann Constant:  k = 1.308662 * 10^-23 J/K

INV 9:  Molar Volume of Ideal Gas:  Vm = 0.02241383 m^3/mol

According to the Casio fx-650 manual, these values are based on 1978 Japan Industrial Standards.  

The nice thing is that the units are stated next to the symbol.  

Verdict 

I am really like the keyboard and the contrast of the font colors.  The bright orange and gold really stand out against the black keyboard.   The screen's digits are really nice and big.  As I mentioned before, the keys have a nice feel.  

If you like a folding scientific calculator, you are going to have to search for a vintage calculator.  The good thing about Radio Shack is that their calculators tend to be less expensive than Casio.  

Sources:

"Electronic Calculators"  epocalc.net  Last Updated April 25, 2013.  http://www.epocalc.net/pages/mes_calcs_03.htm   Retrieved December 12, 2020.

Casio fx-650 Operation Manual

Eddie

All original content copyright, © 2011-2021.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 

Review: Victor 930-2 Scientific Calculator

Review:  Victor 930-2 Scientific Calculator

Quick Facts:

Model:  Victor 930-2
Company:  Victor
Type:  Scientific
Years:  2008 to present
Display:  10 digits
Batteries:  Solar with battery backup (LR43/LR1130)
Retail Price:  $17.99
Logic:  Algebraic, AOS
Number of Functions:  154

Product website from Victor:  https://www.victortech.com/product/930-2

Powerful One Line Calculator - The 21st Century Version of the TI-34

The Victor 930-2 calculator has the following features:

*  Trigonometric functions and their inverses
*  Rectangular/Polar Conversions
*  Degrees/Degree-Minute-Second Conversions
*  Logarithms, Power, Exponential
*  Single Variable Statistics
*  Base Conversions with Boolean Functions (AND, OR, XOR, XNOR, NOT)
*  Constant Calculations
*  Fractions

The keys have the same mapping as the original Texas Instruments (one line) TI-34 from the 1980s and 1990s.   There are some keys and functions that are labeled differently:

Victor 930-2:  [ X→M ],   TI-34:  [ STO ]
Victor 930-2:  [ M+ ], TI-34:  [ SUM ]
Victor 930-2:  [ X←→M ], TI-34:  [ EXC ]
Victor 930-2:  [ INV ],  TI-34:  [ 2nd ]
Victor 930-2:  [ DATA ], TI-34:  [ ∑+ ]
Victor 930-2:  [ DEL ], TI-34: [ ∑- ]

The Victor 930-2 has a bigger and clearer numeric display and an on-off switch. 

Constant calculations is something that might be an overlooked feature on some of these calculators, so let's take a look at how it works.  This applies to both the Victor 930-2 and the TI-34. 

Constant Calculations

For selected two argument functions, you can repeat the calculations on the second argument by entering different values and pressing the equals button [=]. 

A  (op)  B [ = ]
C [ = ]    ( C op B )
D [ = ]    ( D op B )
...

op:  +, -, ×, ÷, y^x, x√y, AND, OR

Example 1:
f(x) = x × π,  x = 4, 3, 3.8

4 [ × ] [ INV ] [ EXP ] (π) [ = ]
Result:  12.56637061

3 [ = ]   ×π is stored in memory
Result:  9.424777961

3.8 [ = ]
Result:  11.93805208

Example 2:
f(x) = x^2.5, x = π, 10.2, e

[ INV ] [ EXP ] (π) [ y^x ] 2.5 [ = ]
Result:  17.49341833

10.2 [ = ]     ^2.5 is stored in memory
Result:  332.2771137

1 [ INV ] [ LN ] (e^x) [ = ]
Result:  12.18249396

Example 3: 
B can be a multi-step in constant calculations.

f(x) = x ÷ (4^2 + 3), x = 10, 20, 50

10 [ ÷ ] [ ( ] 4 [ x^2 ] [ + ] 3 [ = ]
Result:  0.526315789

20 [ = ]    ÷(4^2 + 3) or ÷19 is stored in memory
Result:  1.052631579

50 [ = ]
Result:  2.631578947

Fractions

You can enter fractions and calculate with fractions.  However, you can only convert between fractions and decimals if you start with fractions in your calculations.  The calculator has a limit of 10 digits between the whole part, numerator, and denominator. 

Keyboard

The keyboard is OK.  I like the contrast between the black background and the font better on the Victor 930-2. 

I am irked by the protective case, as it is difficult to take the hard shell case off once the calculator is locked in place.  I prefer the slide case of the TI-34.  I may not cover the 930-2 and use a case or the box to protect the calculator. 

Verdict

If you are looking for a TI-34, consider the Victor 930-2 as it is an updated version.  It does the job.  Again, I wish the hard shell case was easier to work with. 

Eddie

All original content copyright, © 2011-2020.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.

Retro Review: Texas Instruments Explorer Plus

Retro Review:  Texas Instruments Explorer Plus

General Information

Company:  Texas Instruments
Type:  Scientific - Algebraic
Display:  10 digits or 5 digits with 2 digit exponents
Power:  Solar
Memory:  1
Years:  1995 - 1997 (two editions).  I have a the 2nd edition.
Original Cost: $24.95
Documentation:  Manual
Datamath page:  http://www.datamath.org/Sci/Modern/TI-32EXPLUS_2.htm

Features
* Trigonometry, Logarithms
* Degree and Radian mode
* 1 Variable Statistics
* Backspace key
* Fractions with simplification
* 2 Stored Operations (Macros)
* Random Numbers
* Factorial, Combinations (nCr), Permutations (nPr)

Fractions

The Explorer Plus dedicates six keys to fractions. 

[Unit]:  Enter the unit portion of a mixed fraction.  A small "u" separates the whole unit and its fraction.

[ / ]:  Use this to separate a fraction's numerator and denominator.  This is not the same as the division key [ ÷ ].

[ F <> D]:  Change a result from fraction to decimal and vice versa.  Changing to a fraction is does not always change the decimal to the fraction

[ Simp ]:  Use this key to simplify fractions.  I'll talk about this in a bit.

[ A b/c ]:  Change an improper fraction to a mixed fraction.

[ x<> y ]:  Exchange entries.  This works for operations outside the fraction commands. 


Changing to a mixed fraction with the [ A b/c ] key

Example:  Change the improper fraction 74/11 to a mixed fraction.

Keystrokes:  74 [ / ] 11 [ A b/c ]

Result:  6 u 8/11

Simplifying a Fraction

If a result has the display "N/D → n/d" on the left side, this means the fraction can be simplified.  Fractions can be fully simplified, or you can provide a factor. 

Example:  Fully simplify 88/55.

Keystrokes: 88 [ / ]  55 [ = ] [Simp] [ = ]

Result: 8 / 5

Press [ x<>y ] to get the factor used to reduce the fraction, in this case, it would be 11.

Example:  Reduce the fraction 284/404 by a factor of 2.

Keystrokes:  284 [ / ] 404 [ = ] [Simp] 2 [ = ]

Result:  142 / 202

π and Fractions

In Radians Mode, you can work with fractions involving π.  The display will show "Pi". 

Example:  π/4 + 3π/6

Keystrokes:  [ 2nd ] [ π ] (DR>) until RAD shows in the display

[ π ] [ / ] 4        Display:  Pi/4
[ + ] 3 [ π ] [ / ] 6      Display:  3Pi/6
[ = ]     Display:  9Pi/12

Result: 9π/12

For the decimal answer, press [ F<>D ] to get 2.35619449.

Other Keys of Interest

Integer Division

The integer division [ INT÷ ] will display the quotient and remainder of the division problems of two integers.  The displays the quotient by Q and remainder by R.  If you use the result in future calculations, only the integer portion is carried over. 

Example:  Use the integer division command on 128 ÷ 35

Keystrokes:  128 [ INT÷ ] 35 [ = ]

Result:  Q:  3,  R:  23


Random Numbers

The RAND command on the Explorer Plus has two functions:

RAND by itself:  a three digit number between 0.000 and 0.999.  Press [ 2nd ] [ = ] (RAND)

Integer Random Number:  You can get a random integer from 1 to n (up to 100) by the this keystroke sequence:  1 [ 2nd ] [ = ] (RAND) n [ = ].

Example:  Generate a random integer from 1 to 50.

Keystrokes:  1 [ 2nd ] [ = ]  (RAND) 50 [ = ]

Results may vary.


 Stored Operations

You can store simple operations in one of two OP registers, OP1 and OP2.  The operations that can be included are +, -, *, ÷, y^x, INT÷, y^(1/x), nCr, nPr, and random numbers.

Example:  Store x + 6 in OP1. 

[CE/C] (or suitable number) [ + ] 6 [ OP1 ]

11 + 6, 15 + 6, 28 + 6

11 [ OP1 ]  Display:  1        17
15 [ OP1 ]  Display:  1       21
28  [ OP1 ] Display:  1      34

You can repeat operations. 

Clear stored operations by either pressing [ON/AC], which will clear everything, or pressing [2nd] (

Verdict

I really like the the Explorer Plus and I think it would have a made a great base for the current TI-30X generation.  Texas Instruments could have used the TI-40 College (France), which added the rectangular/polar and degrees/degrees-minute-seconds conversion, along with the DIV command (don't know what that does). 

This is a solid calculator for a basic scientific calculator.  I like the emphasis on fractions and it contains the basic scientific calculator functions. 

Eddie

All original content copyright, © 2011-2018.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.  Please contact the author if you have questions.

Review: Casio fx-55 Plus

Review:  Casio fx-55 Plus

General Information

Company:  Casio

Type:  Fractions, Elementary Math

Memory:  1

Battery:  Solar with battery backup (1 LR44)

Years:  2012 - current

Cost:  $10.00 - $20.00, I paid $12.99

Operating Logic:  Algebraic

Target Audience:

* Elementary and middle school students

* Anyone who wants a few more functions than the regular four-function calculator, but not a scientific calculator

* You want a calculator with an emphasis on fractions

Features

The major emphasis on the Casio fx-55 Plus is on fractions.  We’ll discuss this in the next section in detail.

The screen has a textbook display, meaning fractions and all other calculations are displayed as you would write them.  Fractions are simplified.  If MathO (Math Output) is selected, square roots and terms of pi (π) shown in exact form.  If LineO is selected, all answers (except fractions) are shown in decimal form.  No matter what the display mode is, you can always decimal approximation by pressing [SHIFT] [ = ].

Example (MathO):

√12 returns 2 √3

5^2 * π returns 25π

You enter expressions the way you would write them with the Casio fx-55 Plus.  The display is a mutli-line display, the expression on the top of the screen and the answer is on the bottom of the screen. 

The keyboard is simple where only four keys have shifted functions.  The OFF function is shifted as well. 

Other functions include reciprocal, random numbers, including random integers, and calculations in Degrees-Minutes-Seconds [ ° ‘ “ ]. 

The memory has four dedicated keys: store, recall, add to memory (M+), and subtract from memory (M-).

The percent keys work a bit differently from the normal four-function calculators (and is not very intuitive). 

[%] divides the argument by 100 and that’s it.  Its fine when you are working with multiplying or dividing percentages, but adding and subtracting percent will take an algorithm:

X + Y%:  enter X + X * Y %

X – Y%:  enter X – X * Y %

[>%] multiplies the result by 100 and displays the answer in percentage notation. 

Example:  3 [ = ] [ SHIFT ] (>%) returns 300%

Let’s Talk Fractions

The fraction keys are marked lime green on the Casio fx-55 Plus.  Let’s go over the keys in detail:

[ []/[] ] (1st key from the left):  fraction template

[ [] []/[] ] (2nd key from the left):  mixed number template

[ F←→D] (3rd key from the left): switches the result between exact (fractions, exact square roots, terms of π) and decimal answer

[ a b/c ←→ d/c ]:  (4th key from the left)

Manual Simplified mode:  This key does nothing.

Auto Simplified mode: This key converts the result between improper and proper fraction notation. 

[ Simp ]:  calls the simplify conversion to the entry.  In Manual Simplified mode, any fraction that is not reduced to its irreducible form will have a down arrow indicator ( ↓ ).  Also executing Simp in Manual Simplified mode not only returns the reduced fraction, but the factor used into reducing such fraction.

[x^-1]:  The reciprocal function

I also want to point a very handy key, the remainder division function ( [÷R]), which is located on the bottom right hand corner of the keyboard.  This function returns both the quotient and remainder. 

Example:  77 ÷R 13 returns 5, R = 12 

Only the quotient is stored in last answer (Ans).

Let’s compare this Casio fx-55 Plus with an older fraction oriented calculator, the Texas Instruments Math Explorer (aka TI-12). 

Comparison:  Casio fx-55 Plus (2012-present) vs. Texas Instruments Math Explorer (1978-1998)

TI Math Explorer	Casio fx-55 Plus
1 line display	Multi-line, textbook display
No shifted functions	4 shifted functions
N/A	Degrees-Minutes Seconds calculations, random numbers and integers
Constant arithmetic storage function through the [ Cons ] key.	N/A
10^n is limited to integers 0-7	10^x allows for all real numbers between up to, but not including, 100.  Used to work with numbers in scientific notation
Int÷ works with only positive integers	÷R works with real, positive numbers (any non-positive numbers makes ÷R work like ÷)

Verdict

I like this calculator for middle school and elementary students. The Casio fx-55 Plus presents a few extra functions but without the many scientific functions that may intimidate some students.  (emphasis on some)  I wish the percent would work like we would write expressions when it comes to addition or subtraction (i.e. X + Y% instead of X + X * Y%), but this is understandable.  I also wish the proper/improper toggle worked in Manual Simplified mode.

The display is great because the user can see the expression and answer at the same time.  I really like that this calculator also returns exact answers in calculations involving square roots and π. 

I can see this calculator being used beyond the classroom, especially in everyday basic math calculations. 

In any case, the Casio fx-55 Plus serves a great introductory calculator.

Eddie

All original content copyright, © 2011-2018.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.  Please contact the author if you have questions.