10 Helpful ACT Math Calculator Programs for the TI Graphing Series of Calculators

10 Helpful ACT Math Calculator Programs for the TI Graphing Series of Calculators Below are some TI-83/84/85 programs that you can enter into your calculator for the ACT Math Section. Like many of you, I use a TI-83 Plus graphing calculator, so my instructions are customized for that calculator, but they should work fine for the TI-84/85 series as well. Remember that the TI-89 is not allowed on the ACT, because of its CAS (computer algebra system) functionality! Its perfectly OK to use programs on your TI-83/84/85, however, because these calculators lack CAS capability*. ACT Calculator Policy*(EDIT 4/6/17): There is a little-known rule buried in theFAQ and Help section of the ACT website that the program "must not have more than 25 lines of logical text" and "must not call on any other programs." Due to the fact that few test-takers and proctors are aware of this rule, it is unclear whether this restriction will be strictly enforced. Here is the exact text: "Q10: Are there any rules that allowed mathematics-related programs must follow? A: Programs must be written in the language of the calculator. Programs written in a different language, compiled, and loaded onto the calculator are not allowed. In this way, the programs can be examined on the calculator and will use calculator functions. Programs must not be lengthy. The limit is 25 logical lines of code. Programs cannot call another program. Techniques such as compressing code into a data statement are not allowed as a way of getting around this limit. Programs are allowed to change the value of system variables so that results may, for example, be graphed through the normal calculator graphing interface."Unfortunately, although there is the option of using aTI Connect cable (for the TI-83 series) / micro USB cable (for the TI-84 series and above) and downloading the TI Connect software, this software is buggy / hard to use for some, and doesnt work on many operating systems. If you can get the software to work, then you can download additional formulas for this software here. If you want to try it out, then check out thisinstructional video by Brooke Hanson from SuperTutor TV, who explains every step of the process. Feel free to give this software a try if you like, but here, I will be teaching you how to enter some of these programs the old-fashioned way: by hand. If you have a friend who has programmed these formulas into his/her calculator already, then you can also use aLink Cable (TI-83) orMini USB to Mini USB Cable (TI-84 and above) totransfer the programs directly from your friend's calculator to yours. In my opinion, the key is quality over quantity. It's easy to simply download every program you can find, but it helps to find a few useful programs and stick with those.Any suggestions for additional programs, please let me know at mcelroy@post.harvard.edu. If possible, please include the source code of the program(s)! HOW TO ENTER THE FORMULAS INTO YOU R CALCULATORImagine your Texas Instruments calculator buttons as a series of rows (across) and columns (up and down). This will help me point you toward the right buttons.The program "PRGM" button is row 3, column 2: press that button first. Then, select Create New and give your program a name using the green Alpha Keyrow 2, column 1 and the green letters written above the keys. The key is the STO- Key (row 8, column 1) directly above the "ON" key.The =, = and = keys can be found under the Test Menu accessible through the 2nd key (row 1, column 1). Prompt can be found within the PRGM menu (PRGM / I/O)Disp can also be found within the PRGM menu (PRGM / I/O)Sqrt refers to the square root button (2nd key / row 5, column 1)1) Quadratic Formula SolverPrompt APrompt BPrompt C(-B+sqrt(B^2-4AC))/(2A)--X(-B-sqrt(B^2-4AC))/(2A)--YDisp XDisp YPro tip: to include imaginary (nonreal) results, select "Mode" and change "Real" to "a+bi". 2) Distance FormulaPrompt A (x1)Prompt B (y1)Prompt C (x2)P rompt D (y2)Sqrt((A-C)^2+(B-D)^2)-- EDisp "Distance ="Disp EStop3) Area of Triangle Using 3 SidesDisp "Side A"Input ADisp "Side B"Input BDisp "Side C"Input CA+B+C--XX/2--DSqrt((D)(D-A)(D-B)(D-C))-- EDisp "Area=?Disp EStop4) Midpoint FormulaPrompt A (x1)Prompt B (y1)Prompt C (x2)Prompt D (y2)(A+C)/2-- E(B+D)/2-- FDisp "X Midpoint="Disp EDisp "Y Midpoint="Disp FStop5) Sum of X Consecutive IntegersDisp "Sum of"Input S.5S(S+1)--ADisp "Sum of 1 to S="Disp AStop6) Volume and Surface Area of a SphereDisp "Radius="Input R(4/3)PiR^3--Z4PiR^4-- YDisp "Volume="Disp ZDisp "Surface Area="Disp YStop7) Volume and Surface Area of a ConeDisp "Radius="Input RDisp "Height="Input HDisp "Slant="Input S(1/3)PiR^2H--VPiR^2+PiRS-- WDisp "Volume="Disp VDisp "Surface Area="Disp WStop8) Converting Between Fahrenheit and CelsiusClrHomeMenu("FROM","FAHRENHEIT",1,"CELSIUS",2,"KELVIN",3)Lbl1PromptF5(F-32)/9CC+273.15KGoto4Lbl2PromptCC+273.15K9C/5+32FGoto4Lbl3PromptKK-273.15C9C/5+32FLbl4ClrHomeDispF,C,KOutput(1,1," F")Output(2,1,"C")Output(3,1,"K")Stop9) Standard DeviationThis one isn't an actual program, but it works just as well. On the TI-83/84/85 series, you can calculate standard deviation using the2nd/LIST/Math Menu, making sure to add braces around your numbers and commas to separate them, like this: stdDev ( {1,2,3,4,5} = 1.5810) Radical Expression Simplifier:ClrHome:Disp "SIMPLIFIES xth root of N" (MATH5):Prompt X,N:For(F,iPart(Xx\/N+.1),2,-1):If fPart(N/F^X:End:Output(5,1,F:2+iPart(log(F-K :Output(5,K,"*:Output(5,K+1,X:K+iPart(log(X-K:Output(5,K+2,"x\/:Output(5,K+4,N/F^XorLbl 3prgm CLEARDisp INPUT THE NUMBERDis UNDER THEInput RADICAL: ,XiPart(Sqrt (X) + 1 ALbl 1If fPart(X/A^2)=0ThenGoto 2Else(A-1) AGoto 1Lbl 2prgmCLEARText (1,1,A, Sqrt(,X/A^2,))PauseMenu(FIND ANOTHER,YES,3,NO,4)Lbl 4StopHave fun and good luck!-Brian