Section 4-2 "Powers and Exponents"

Technology objective: Students will explore patterns using the exponent keys on both the TI-34 and the TI-81 calculators.

Lesson: Students should already be familiar with using the exponents keys on the TI-34. (They can refer back to their "lab" worksheets if they have forgotten.) On the TI-81 calculator, the students will need to look for the "^" key. They will insert this symbol in between the base and the power. Have them try a few problems on their own.

Now have students look for the key marked 10 . First, ask them how to access it. Then have the students "explore" the key. After a few minutes ask them to describe what they think the function of that key is in their journals.

Reinforcement:

Game 1... This activity was found in the 1992 yearbook Calculators in Mathematics Education from the Statewide In-Service Programs on Calculators in Mathematics Teaching written by Bright, Lamphere, and Usnick. This game will involve using the 10 key. The purpose of this game is to develop "notions of expanded notation in a calculator environment." The students will be responsible for making the number 3456 appear in the display, under the restriction of using the 10 key once for each digit. Have them record the keystrokes that provide the correct response. Have them try this with a larger number. Also have them try this with a smaller number, for example 0.123.

Game 2... This activity was also found in the same article mentioned above. The purpose of the game is to involve the students exploring the use of exponents - positive and negative!

1) Clear the calculator display.

2) Enter the following number: 63418275. These eight digits are the "space invaders." In order to protect planet Earth, you must shoot them down one by one by changing each digit to 0.

3) Digits must be shot down in ascending order. That is, you must first eliminate the 1, then the 2, then the 3, and so on.

4) For each digit in turn, record a keystroke sequence below that includes 10 . Then carry out the keystroke sequence.

5) If the correct digit is removed, proceed to the next digit. If not, reenter the previous display and try again.

Digit...................Keystroke Sequence...................Number in Display

1

2

3

4

5

6

7

8