A mixed number contains a whole number and a fraction. To estimate fractions with mixed numbers, add the benchmark of the fraction to the whole number.
- Choose benchmarks for the fraction in the mixed number
The benchmark is the reference for estimating the fraction. Let 0, 1/2 and 1 be the benchmarks for the fraction.
- Determine whether the fraction is closest to 0, 1/2 or 1
If the numerator is very small compared to the denominator, select 0 as the benchmark. For example, with 5/100, the numerator, 5, is very small compared to the denominator, 100; therefore, 0 is the benchmark. If the numerator is nearly half the denominator, choose 1/2 as the benchmark. For example, with 50/120, 50 is nearly half the value of 120; therefore, 1/2 is the benchmark. Finally, if the numerator is nearly equal to the denominator, choose 1 as the benchmark. For example, in the fraction 234/256, 234 is almost equal to 256; therefore, 1 is the benchmark.
- Estimate the mixed number by adding the benchmark to the whole number
Considering the fraction 9 7/16, 9 is the whole number and 7/16 is the fraction. The benchmark for 7/16 is 1/2 since the numerator and denominator are nearly equal. To obtain the estimate, add 9 to the benchmark, 1/2. Therefore, 9 7/16 is estimated at 9 1/2.