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Key
Idea
There is more
than one way to
estimate sums and
differences. |
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Vocabulary
• front-end
estimation
• rounding (p. 26) |
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Estimating Sums
and Differences |
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| How can you estimate sums? |
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Students at Skyline Elementary collected
aluminum cans for recycling. About how
many pounds of cans did they collect in all? |
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Estimate
398 + 257 + 285 + 318. |
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| Jon
used rounding. |
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Kylie used front-end estimation
and adjusted the estimate. |
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