[. . . ] TI-15 A Guide for Teachers TI. 15: A Guide for Teachers Developed by Texas Instruments Incorporated Activities developed by Jane Schielack About the Author Jane Schielack is an Associate Professor of Mathematics Education in the Department of Mathematics at Texas A&M University. She developed the Activities section and assisted in evaluating the appropriateness of the examples in the How to Use the TI-15 section of this guide. Important Notice Regarding Book Materials Texas Instruments makes no warranty, either expressed or implied, including but not limited to any implied warranties of merchantability and fitness for a particular purpose, regarding any programs or book materials and makes such materials available solely on an "as-is" basis. In no event shall Texas Instruments be liable to anyone for special, collateral, incidental, or consequential damages in connection with or arising out of the purchase or use of these materials, and the sole and exclusive liability of Texas Instruments, regardless of the form of action, shall not exceed the purchase price of this book. Moreover, Texas Instruments shall not be liable for any claim of any kind whatsoever against the use of these materials by any other party. [. . . ] Then they can use the calculator to connect dimes to one tenth (0. 1) of a dollar ($13. 14 has 131 dimes or tenths) and pennies to one hundredth (0. 01) of a dollar ($13. 14 has 1314 pennies or hundredths). For older students, connect the place-value patterns to conversions between metric units. For example, a measurement of 324 centimeters can also be recorded as 32. 4 decimeters (or rounded to 32 dm) because 1 dm = 10 cm, or it can be recorded as 3. 25 meters (or rounded to 3 m), because 1 m = 100 cm. 2000 TEXAS INSTRUMENTS INCORPORATED TI-15: A Guide for Teachers 31 The Value of Place Value, Part A Collecting and Organizing Data Name ___________________________ Date ___________________________ 1. Use your base-ten materials and your calculator to explore how many tens, hundreds, and thousands are in a number. What patterns do you see? Number Number of Thousands Number of Hundreds Number of Tens Analyzing Data and Drawing Conclusions: Patterns 2. Write 5 numbers that have 15 tens. __________________________________________________________________________ 3. Write 5 numbers that have 32 hundreds. __________________________________________________________________________ 4. Write 5 numbers that have 120 tens. __________________________________________________________________________ 2000 TEXAS INSTRUMENTS INCORPORATED TI-15: A Guide for Teachers 32 The Value of Place Value, Part B Collecting and Organizing Data Name ___________________________ Date ___________________________ 1. Use your base-ten materials and your calculator to explore how many tenths, hundredths, and thousandths are in a number. What patterns do you see? Number Number of Tenths Number of Hundredths Number of Thousandths Analyzing Data and Drawing Conclusions: Patterns 2. Write 5 numbers that have 15 tenths. __________________________________________________________________________ 3. Write 5 numbers that have 32 hundredths. __________________________________________________________________________ 4. Write 5 numbers that have 120 tenths. __________________________________________________________________________ 2000 TEXAS INSTRUMENTS INCORPORATED TI-15: A Guide for Teachers 33 What's the Problem? Overview Students will connect number sentences to problem situations and use addition, subtraction, multiplication, and division to solve the problems. Grades 2 - 5 Math Concepts addition, subtraction multiplication, division (Grades 3 - 5) number sentences (equations) inequalities (Grades 3 - 5) Materials TI-15 counters pencil student activity (page 37) Introduction 1. On a sentence strip or on the overhead, display a number sentence such as "8 + 2 = ?" Have students brainstorm situations and related questions that this number sentence could be representing. For example, "If I bought eight postcards on my vacation and I had two postcards already at home, how many postcards do I have now?" 2. If necessary, have students act out the situation with counters and determine that the value of "?" is 10. Demonstrate how to display this equation on the calculator, and how to tell the calculator what the value of ?Have students brainstorm situations and related questions that this number sentence could be representing. For example, "I had some money in my pocket, and I spent 10 cents of it. How much money did I have in my pocket to begin with?" Have students practice the keystrokes necessary to display this equation and test the value they determine for "?". Over a period of time, continue to introduce students to different types of number sentences to explore. x 4 = 2 (which has no whole number solution). 2000 TEXAS INSTRUMENTS INCORPORATED To display this equation on the calculator, put the calculator in Problem Solving mode by pressing the < key. [. . . ] Integer division function has been selected (appears only when cursor is over division sign). You must press to complete the selection process. 2000 TEXAS INSTRUMENTS INCORPORATED TI-15: A Guide for Teachers B-1 Error Messages Message Arith Error Syn Error P 0 Error Op Error Overflow Error Underflow Error C Meaning Arithmetical error. You entered an invalid entry or an invalid parameter; for example, L5 . You entered an invalid or incorrect equation; for example, 5++2 or missing parenthesis. [. . . ]