Lesson 1: Estimate Fraction Sums and Differences

Property

To estimate if the sum of two fractions is greater than 1, compare each fraction to the benchmark of $\frac{1}{2}$.
If both fractions are greater than $\frac{1}{2}$, their sum will be greater than 1.
If $\frac{a}{b} > \frac{1}{2}$ and $\frac{c}{d} > \frac{1}{2}$, then $\frac{a}{b} + \frac{c}{d} > 1$.

Examples

Property

To assess the reasonableness of a sum or difference, estimate the result by rounding each fraction to the nearest benchmark ($0, \frac{1}{2}, 1$) or each mixed number to the nearest half.
Compare this estimated result to the given answer.
If the estimate and the answer are close, the answer is reasonable.

Examples