Reverse The Order - Sharp EL-531RH Teachers Manual

Reverse the Order

• • • • • • • • • • • • • • • • • • • • • Objective • • • • • • • • • • • • • • • • • • • • •
Develop a variety of mental methods of computation.
Estimate and approximate solutions to problems.
• • • • • • • • • • • • • • • Explanation of the activity • • • • • • • • • • • • • •
Enter any 2-digit number into the calculator.
Reverse the order of the digits through simple calculator operations.
While working on this activity, students should develop their skills of mental mathematics.
They should also be interpreting and generalizing their answers.
• • • • • • • • • • • • • • • • • Using the calculator • • • • • • • • • • • • • • • • •
Press the following buttons and then start operation.
Example A:
To reverse the order of 58:
85 58
58 27
Solution: Add 27 to 58 to get 85.
Now try using a 3-digit number.
Example B:
Enter 432 into the calculator
432
234
Solution: Add 198 to 234 to get 432.
Calculator functions used: Addition, subtraction
234
198
85-58=
58+27=
432-234=
234+198=
8
Junior high school
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