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How do you know if the sum or difference in an equation involving fractions is reasonable? . For example:. =. +. In this lesson you will learn how to determine the reasonableness of sums and differences using benchmark fractions. Numerator : The number of parts being considered. 1.
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How do you know if the sum or difference in an equation involving fractions is reasonable? For example: = +
In this lesson you will learn how to determine the reasonableness of sums and differences using benchmark fractions.
Numerator: The number of parts being considered 1 3 Denominator: The number of equal parts in the whole
Benchmark Fractions 0 whole 1 parts 0 1
Estimating with whole numbers Students in the craft club made 48 white paper snowflakes and 54 glittery silver icicles for the winter ball. How many decorations did they prepare in all? about Both numbers are close to 50. 50 + 50 = 100 100 10 1000
Estimating with fractions Rounding to the nearest half 0 1 0 1 is closest to is closest to
There are two main uses for rounding fractions to the nearest half 1 • Rounding fractions to estimate • sums and differences ∙ before calculations ∙ when exact answers are not needed • Rounding fractions to determine • reasonableness of sums and differences 2 ∙ during or after calculations
Rounding fractions to estimate sums and differences 1 0 1 0 1 1 1 = = + about +
Sophia’s hermit crab eats of a cup of rice and of a cup of fruit per week. = 0 = about + +
2 Rounding fractions to determine reasonableness of sums and differences 0 1 1 = = - -
Tyler mowed of the lawn on Monday and of the lawn on Tuesday. His father said that he mowed of the lawn in all. x about = +
In this lesson you have learned how to determine the reasonableness of sums and differences using benchmark fractions.