Spotlight: Sharp EL-5200 As we come on the 13th (April 16) anniversary of this blog, I want to thank you. Blogging about mathematics and calculators is a joy in my life and I’m grateful for your support. Today’s spotlight is about an early graphing calculator, which is a rare collector’s item today: the Sharp EL-5200, also known as the Sharp EL-9000. Quick Facts Model: EL-5200/EL-9000 Company: Sharp Timeline: 1986 – late 1980s Type: Graphing, Programmable Memory: 5,120 bytes Power: 2 x CR2032 batteries Keyboard There are excellent reviews and articles on the Sharp EL-520 ..read more

Numworks Updates Apologies that I have not done anything with Numworks in what seems to be forever.  The current official software is Version 22: *  Polar and algebraic form of complex numbers are displayed in the expanded results in Calculator mode * Chi-Square test added to the Inference app *  Better navigation of the Elements (Periodic Table) app *  The toolbox button also can escape the toolbox without selecting a command or function More information: https://www.numworks.com/calculator/update/version-22/ Version 23 is in beta stage and some the intended offerings ..read more

Swiss Micros SM32: Simulating a Choose Menu The following technique should work for the HP 33S and HP 35S, but most likely HP 32S/32SII due to the lack of memory (you could shorten or eliminate the messages, I suppose.). What Is Needed We will need at least two labels. The user flags as needed. For the DM32, the user flags are from Flag 0 to Flag 4. This allows for up to five choices. A choice variable. This variable holds the user’s choice from the menu. The algorithm presumes that the user will always enter a valid choice. Clever calculation, as we start with the reference value in the X ..read more

Radius and Apothem of Regular Polygons On this blog, let’s calculate the lengths of a regular polygon’s radius, apothem, and area knowing only the side length and internal angle. A regular polygon is a polygon in which every side has an equal length, and every internal angle is equal. Let x be the length of one side of the regular polygon, and θ be the internal angle of the polygon where: θ = (n – 2) / n × 180° The radius (r) of the regular polygon is a line segment from a vertex to the center of the polygon. The radius bisects the vertex, therefore cutting the internal angle in half ..read more

 TI-30Xa Algorithms: Linear Regression Welcome to the March 2024 installment of TI-30Xa Algorithms. Linear Regression with a TI-30Xa? Today’s task is to fit bi-variate data to the line: y = m * x + b with the TI-30Xa. What? This calculator does not have a linear regression mode. Yes, with it is possible. We are going to use the technique shown in by the TI-36 Solar Guidebook from 1985 (see Source below). The TI-36 Solar was part of Texas Instruments’ line in the late 1980s and the early 1990s. You can read my review on the TI-36 Solar from September 26, 2020 here: https://edspi3141 ..read more

 HP Prime and Casio fx-CG 50: Dedekind Sums Definition The Dedekind Sum is defined as follows: Let P and Q be relatively prime integers, that is GCD(P, Q) = 1. Then S is the Dedekind sum as: S = Σ( ((I ÷ Q)) × ((P × I ÷ Q)), for I=1 to Q) The double parenthesis around the terms I ÷ Q and P × I ÷ Q signify a custom function: (( X )) = 0, if X is an integer X – FLOOR(X) – 1/2, if X is not an integer If X is positive, X – INTG(X) – 1/2 HP Prime: DEDEKIND EXPORT DEDEKIND(p,q) BEGIN // 2024-02-21 EWS LOCAL s,i,a,b; // Calculation IF CAS.gcd(p,q)==1 THEN s:=0; FOR i FROM 1 TO q DO ..read more

  Casio fx-7000G vs Casio fx-CG 50: A Comparison of Generating Statistical Graphs Today’s blog entry is a comparison of how a histogram, normal distribution graphs based on statistical data, scatter plots, and linear regression plot are generated on Casio’s first graphing calculator, the fx-7000G (1985) and the most recent (as of this blog post), the fx-CG 50 (2016). For the curious, the SD2 and LR2 modes are the statistical plot modes of the fx-7000G. The procedures for the fx-7000G are the same for the fx-6500G, fx-7500G, fx-8000G (and equivalents) and fx-6300G. The procedures for t ..read more

Casio fx-9750GIII and fx-CG 50: Playing Games with the Probability Simulation Mode The Probability Simulation add-in has six types of probability simulations: * Coin Toss * Dice Roll * Spinner * Marble Grab * Card Draw * Random Numbers The add-in application is available for the following calculators: * Casio fx-9750GIII and fx-9860GIII (and Graph 75/85/95 series, Graph 35+ E II) * Casio fx-CG 10/20 and fx-CG 50 (and Graph 90+E) * Casio fx-9860G I believe on the fx-9750GIII and fx-9860GIII, the Probability Simulation Add-In is available out of the box. For others, the add-in can be dow ..read more

DM42 and DM41X: Timing Programs How Long Does it Take? There is a convenient way of timing programs on the Swiss Micros DM42 and DM41X. This is accomplished by the TIME function. The TIME function returns the time, initially shown in HH:MM:SS format. HH represents hours, MM represents minutes, and SS represents seconds. The time is stored internally in HH.MMSS format. We will also use the HMS- function. The HMS- subtracts two time values in HH.MMSS format. A format that time the performance of an algorithm: TIME STO ## (store in any variable desired) ... [main code here] … TIME RCL ## (recal ..read more

Fun with the TI-81 (March 2024 Edition) TI-81 SCATTER Produces a scatter plot. Size: 52 bytes Code: If Dim{x}=0 Disp “NO DATA” If Dim{x}=0 Stop ClrDraw 1→I Lbl 0 PT-On({x}(I),{y}(I)) IS>(I,Dim{x}) Goto 0 DispGraph Note: Dim{x} returns the number of data points in the statistics list {x}. Keystrokes: [ VARS ], DIM, 7: Dim{x} TI-81 ANGLES Given three pints, the internal and external angle are calculated. Size: 196 bytes Code: Deg Disp “SIDE PT (S,T)” Input S Input T Disp “CORNER (M,N)” Input M Input N Disp “SIDE PT (U,V)” Input U Input V (S-M)*(U-M)+(T-N)*(V-N)→D ..read more