When we are estimating a sum or a difference of any value, we must focus on place value. But when we are working with fractions it is a bit different. This selection of worksheets has students take two mixed numbers that do not share the same denominator and you are tasked to find the sum or difference between the two. Your first goal should be to get the mixed numbers on the same footing (denominator).
How do you estimate the sum and difference of fractions? A sum is an answer in an addition problem. You can also estimate the sum of fractions. To estimate a sum of two fractions, round the fractions to the nearest half. Here is an addition problem. 38 + 17 = ? First, round each fraction to the nearest half.
Let's start with 38. For a whole it is divided into 8 parts, 12 = 48. 38 is rounded to 12.
For a whole divided into 7 parts, one-half is between 37 and 47. 17 is rounded 0.
3812 ≈ 12 ≈ 0
Then, rewrite the problem and find the sum. 12 + 0 = 12. The estimated sum is 12.
When talking about a difference, you are talking about subtraction. Estimating the difference between fractions and mixed numbers is similar to estimating sums. Round each fraction or mixed number and then subtract to find the estimate.
45 - 37 = ____________
First, round each fraction to the nearest half.
For a whole divided into 5 parts, one-half is between 25 and 35. 45 is rounded to 1.
For a whole divided into 7 parts, is one-half is between 37 and 47. 37 is rounded to 12.
4537 ≈ 1 ≈ 12
Then, rewrite the problem and subtract.
1 - 12 = 12. The estimate difference is 12. These worksheets explains how to estimate sums and differences with fractions. Your students will use these activity sheets to learn how to estimate the sums and differences of mixed numbers by rounding according to the fraction.