Teacher Notes
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TIMS Bit
Pressing 1 + = = = on a calculator with an addition constant will cause the calculator to count by ones. To count by twos, press: 2 + = = =. Otherwise students can press 2 + 2 + 2 + 2 + 2 + . . . or 2 + 2 = + 2 = + 2 = + 2 = . . . . You do not necessarily need a calculator to do this activity. However, students will use skip counting on the calculator in later units on multiplication and decimals.
Discuss the results. Did students predict that it would take half as long to count by twos? Were their predictions close? Why or why not?
C. Calculator Counting
Work with a partner to find how long it will take to count to 100. One partner will count. The other will time how long the counting takes. Take turns.
- Use a calculator to count by ones to 100. How long did it take?
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- Predict how long it would take to count by twos to 100. Use a calculator to count by twos to 100. How long did it take?
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