Sharp EL-531RH Teachers Manual page 34

Last Digits
• • • • • • • • • • • Using the activity in the classroom • • • • • • • • • • •
It is probably best to first introduce the activity as a class to give the students an opportunity to
make estimates before using their calculators. Once the class has shared their initial ideas, they can
be given time to investigate any patterns they discover.
• • • • • • • • • • • • • • • Points for students to discuss • • • • • • • • • • • • • •
After investigating patterns on their own, students should share their discoveries with the rest of
the class.
Further Ideas
• Examine the first 20 prime numbers. Except for the number 2, they all end with an odd last
digit. Repeat the procedure for the last digits of 3, 7, and 9. Find all the prime numbers
between 1 and 201.
• Find the last digits to:
1. the answers to the multiplication tables.
2. the square numbers.
3. other number sequences such as the cube numbers and triangle numbers.
• Find the two consecutive numbers whose product is 6006.
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Junior high school