Estmate fraction sums and differences (like denominators)

9/10  $\approx$  

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• 1/2

• 1

1/10 $\approx$  

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• 1/2

• 1

Use benchmarks to estimate 9/10 -1/10 =

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• 1/2

• 1

Round 1/3 using benchmarks.

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• 1/2

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Round 2/3 using benchmarks.

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• 1/2

• 1

Estimate the sum 1/3 + 2/3

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• 1/2

• 1

Round using 4/9 using benchmarks.

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• 1/2

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Round 1/9 using benchmarks.

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• 1/2

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Estimate the sum of 4/9 + 1/9

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• 1/2

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Round 10/11 using benchmarks.

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• 1/2

• 1