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Key Idea
Look Back and Check is the final phase of the problem-solving process. |
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Look Back and Check |
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| What
are the last steps in solving a problem? |
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The Redwood Tree To celebrate
the 200th birthday of the
United States, a class planted
a 6-year-old redwood tree on
July 4, 1976. How old was that tree on July 4, 2002? |
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| Step
1: Have you checked your answer? |
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Check that you answered
the right question. |
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Use estimation and
reasoning to decide if
the answer makes sense. |
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Ann found the total number
of years. |
1970 to 2000 is 30 years so
the answer makes sense. |
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| Step
2: Have you checked your work? |
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| • |
Look back at your work
and compare it against
the information in the
problem. |
| • |
Check that you used the
correct operation or
procedure. |
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Ann
found the total number
of years, 32 years. |
Ann subtracted to find the total
number of years from 1976
to 2002. Then she added 6 years
for the age of the tree when it
was planted. |
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Talk
About It |
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1. |
Steve
wrote the answer at the right for the Redwood
Tree problem. What mistake did he make? |
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