and numbers and no spaces. Press after typing the name. You are now in the Program Editor. Each line of code begins with the colon character ( : ).

Transcription

1 NEW! Calculator Coding Explore the basics of coding using TI Basic, and create your own program. Created by Texas Instruments for their TI Codes curriculum, this activity is a great starting point for learning the basics of coding using the TI Basic programming language. In this activity, students will follow instructions to create a program to display text and a program to evaluate an expression for certain inputs. Students will then use the skills they learned to write their own code. MATERIALS NEEDED TI calculator TI-83 Plus and up (one per student or group) Programming Basics handout (one per student or group)* Instructions for TI-Nspire are available at education.ti.com/en/us/solutions/ti-codes *Included in this Club Activity Book and available for download at PART 1: PROGRAMMING BASICS In the first part of this activity, students will use the TI Basic Program Editor to create, edit and run a program to display text on their calculator screen. Follow the steps below, which are also listed on the student handout. The calculator screen should look like each screen to the right, with slight differences in appearance depending on the TI model being used. Pay attention to the Club Leader Tip boxes for answers to common questions. Club Leaders should run through the programming themselves before trying it with the whole club. Creating your program 1. Turn on your TI calculator and press the key. Select NEW by using the arrow keys. Select Create New by pressing. 2. Name your program. Our program name will be HELLOXY. It can be any name that has eight characters or less, starts with a letter and includes only uppercase letters Club Leader Tip: If you use a name that has already been used, you will edit the old program rather than create a new one. and numbers and no spaces. Press after typing the name. You are now in the Program Editor. Each line of code begins with the colon character ( : ). 3. The key now displays new menus with the commands used in TI Basic. You must select commands from each menu rather than type them on the screen. Press the key. Choose the I/O menu by using the arrow keys. This menu contains all of the commands affecting input and output. Select Disp. The Disp command is used to display text on the HOME screen. Club Leader Tip: You cannot type in the programming commands. All keywords in a program are selected from the menus. The text displayed is actually just a readable symbol (token) for the programming command. 4. Type a phrase in double quotation marks. This is called a string. Your string must start and end with quotation marks. Without the quotes, the program thinks you mean something completely different. Press to turn on alpha-lock while you type in the string. Your program is complete! Let s run it now MATHCOUNTS Club Activity Book 27

2 Running your program 1. To run the program, press ( ) to return to the HOME screen. There is no need to save with TI Basic; the program is preserved as you type it in. That s why we named the program first. 2. Press. Under the EXEC ( execute ) menu, select your program. 3. Press to paste the program name on the HOME screen. Press again to run the program. Club Leader Tip: If a program generates an ERROR message, there are two options under the error: 1: Quit and 2: Go To. Quit takes you to the HOME screen and Go To takes you into the Program Editor to the place in the program where the error occurred. Editing your program 1. Press. Choose the EDIT menu by using the arrow keys. Select your program and press. We are going to edit this program and add more display statements to it. 2. Move the cursor to the end of the first line of the program and press. A second colon will appear. This is the second line of the program. Press the key. Choose the I/O menu by using the arrow keys. Select Disp again. 3. Type another message in quotes. Remember to press to turn on alpha-lock while you type in the string (note the change in appearance of the cursor when alpha-lock is active). Press again at the end of the second line and add more display statements. You can add as many statements as you like, but it s possible that you could add so many that the resulting text won t fit on the screen all at once. 4. Your program is complete. Let s run it by pressing ( ) and selecting it from the EXEC menu of the key. You ll notice that the first line on the screen reads prgmhelloxy and the last line reads Done. Let s edit the program so that our text displays on a clean home screen. 5. The ClrHome statement clears the HOME screen, but we want this statement to be at the top of the program. While editing your program, place your cursor at the top of the program (on the D of the first Disp statement). Press ( ) and then press to make a new, blank line above the Disp statement. 6. Press the up arrow key to place your cursor on that blank line. Press and use the right arrow key to see the I/O menu and select the ClrHome statement. 7. Scroll to the bottom of your program and press for a new line. Add the Pause statement. You will find Pause on the CTL menu. 8. Quit the editor and run the program. You will see your text displayed on a clean HOME screen. Look closely in the top right corner of the screen and you ll see the busy indicator. That s the Pause statement at work. The program is paused at this point and the user must press to continue. Then the Done message appears at the bottom of the screen MATHCOUNTS Club Activity Book

3 PART 2: USING VARIABLES AND EXPRESSIONS For the second part of this activity, students will learn about the Prompt statement, which is used to make the programs interactive by using variables to store numeric values. Students will also learn about evaluating and storing results of mathematical expressions, and using Disp and Output statements to show the results of stored computations. Club Leader Tip: To delete a program from memory, press, then press, then select 2: Mem Management/Delete... Select 7: Prgm... and press on the program you wish to remove. Programming with Prompt 1. Start a new program. For the first statement of the program, use the Prompt statement found in the I/O menu. The Prompt statement is followed by one or more variable names that ask the user to enter a value for a variable. 2. After the Prompt command, type the name of the variable or variables you want your program to use. In this program we will use the letter A. 3. Use the Disp statement and type A and then the key to display the square A Quit the editor and run the program. After the A=? prompt, type any number. The program displays the square of this number and ends. Entering multiple values with Prompt 1. Edit the previous program. Add,B to the Prompt statement. 2. Change the Disp statement so that it displays the sum A+B. Before this statement, insert a Disp statement that reads SUM=. The equal sign can be found in the Test menu by pressing. 3. Run the program again. Notice the two prompts. The Prompt statement asks for a value for each variable separately. PART 3: COMPUTING A FORMULA Students now know how to create, edit and run simple programs using the Disp, ClrHome, Pause and Prompt commands. Have them practice creating their own programs to calculate values by using some common formulas. Encourage them to use all of the four commands they just learned. Some formula suggestions with accompanying code appear below. Pythagorean Theorem a 2 + b 2 = c 2 Circumference of a Circle C = 2 r Club Leader Tip: There are 27 built-in variables used to store numeric values. The variable names are the letters A through Z and θ ( Theta ). Slope m = (y 2 y 1 )/(x 2 x 1 ) DO MORE WITH THIS ACTIVITY This activity is from Texas Instruments education site On this site you can find extended versions of this activity as well as activities to explore more complex programming functions in TI Basic. There are even more free resources for middle school math educators, called Building Concepts in Mathematics that can be found at MATHCOUNTS Club Activity Book 29

4 Creating your program Programming Basics 1. Turn on your TI calculator and press the key. Select NEW by using the arrow keys. Select Create New by pressing. 2. Name your program. Our program name will be HELLOXY. It can be any name that has eight characters or less, starts with a letter and includes only uppercase letters and numbers and no spaces. Press after typing the name. You are now in the Program Editor. Each line of code begins with the colon character ( : ). 3. The key now displays new menus with the commands used in TI Basic. You must select commands from each menu rather than type them on the screen. Press the key. Choose the I/O menu by using the arrow keys. This menu contains all of the commands affecting input and output. Select Disp. The Disp command is used to display text on the HOME screen. 4. Type a phrase in double quotation marks. This is called a string. Your string must start and end with quotation marks. Without the quotes, the program thinks you mean something completely different. Press to turn on alpha-lock while you type in the string. Your program is complete! Let s run it now. Running your program 1. To run the program, press ( ) to return to the HOME screen. There is no need to save with TI Basic; the program is preserved as you type it in. That s why we named the program first. 2. Press. Under the EXEC ( execute ) menu, select your program. 3. Press to paste the program name on the HOME screen. Press again to run the program. Editing your program 1. Press. Choose the EDIT menu by using the arrow keys. Select your program and press. We are going to edit this program and add more display statements to it. 2. Move the cursor to the end of the first line of the program and press. A second colon will appear. This is the second line of the program. Press the key. Choose the I/O menu by using the arrow keys. Select Disp again.

5 3. Type another message in quotes. Remember to press to turn on alpha-lock while you type in the string (note the change in appearance of the cursor when alpha-lock is active). Press again at the end of the second line and add more display statements. You can add as many statements as you like, but it s possible that you could add so many that the resulting text won t fit on the screen all at once. 4. Your program is complete. Let s run it by pressing ( ) and selecting it from the EXEC menu of the key. You ll notice that the first line on the screen reads prgmhelloxy and the last line reads Done. Let s edit the program so that our text displays on a clean home screen. 5. The ClrHome statement clears the HOME screen, but we want this statement to be at the top of the program. While editing your program, place your cursor at the top of the program (on the D of the first Disp statement). Press ( ) and then press to make a new, blank line above the Disp statement. 6. Press the up arrow key to place your cursor on that blank line. Press and use the right arrow key to see the I/O menu and select the ClrHome statement. 7. Scroll to the bottom of your program and press for a new line. Add the Pause statement. You will find Pause on the CTL menu. 8. Quit the editor and run the program. You will see your text displayed on a clean HOME screen. Look closely in the top right corner of the screen and you ll see the busy indicator. That s the Pause statement at work. The program is paused at this point and the user must press to continue. Then the Done message appears at the bottom of the screen. Programming with Prompt 1. Start a new program. For the first statement of the program, use the Prompt statement found in the I/O menu. The Prompt statement is followed by one or more variable names that ask the user to enter a value for a variable. 2. After the Prompt command, type the name of the variable or variables you want your program to use. In this program we will use the letter A. 3. Use the Disp statement and type A and then the key to display the square A Quit the editor and run the program. After the A=? prompt, type any number. The program displays the square of this number and ends.

6 Entering multiple values with Prompt 1. Edit the previous program. Add,B to the Prompt statement. 2. Change the Disp statement so that it displays the sum A+B. Before this statement, insert a Disp statement that reads SUM=. The equal sign can be found in the Test menu by pressing. 3. Run the program again. Notice the two prompts. The Prompt statement asks for a value for each variable separately.