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Estimating Sums and Differences with Fractions

Answer Keys Here

Aligned To Common Core Standard:

Grade 5 Fractions - 5.NF.A.1

How to Quickly Estimate the Sums and Differences with Fractions - Estimation is an important skill to learn, both in math and in everyday life. However, adding and subtracting with fractions can be complicated. Since they are not whole numbers, but a portion of it. Thus, to estimate sums and differences with fractions, you need to convert the fractions to either a 0, 1/2 or a 1. Let's suppose, and you have to add 9/16 + 5/12. Initially, you need to convert the first fraction to the nearest 1/2 since it is less than 12/16 (3/4) and greater than 4/16(1/4). Now, the second fraction also rounds to 1/2, since, it's higher than 3/12(1/4) and less than 9/12(3/4). If we add 1/2 and 1/2, we get an answer 1, which will be the approximate answer. Students can use these worksheets and lessons to learn how to take estimates of fraction operations.

Printable Worksheets And Lessons

Homework Sheets

You have to love rounding the sums of fractions! Mixed numbers are a whole different ball game.

  • Homework 1 - If the numerator is much smaller than the denominator, then the result will be 0.
  • Homework 2 - To round, a mixed number to the nearest whole number, look at the fraction part. If the fraction is less than 1/2, round down.
  • Homework 3 - If the fraction is greater than or equal to 1/2, round up.

Practice Worksheets

You are supposed to estimate them, not calculate them.

  • Practice 1 - If the numerator is about one half of the denominator, than the result will be 1/2.
  • Practice 2 - If the numerator and the denominator are close to each other than result will be 1.
  • Practice 3 - We have to follow the 3 rules while calculating sum or differences of fractions.

Math Skill Quizzes

Some of these are tough. Take you time to soak in the fraction that you are working with.

  • Quiz 1 - Some times students will just subtract the numerators. Start by finding a common base.
  • Quiz 2 - This whole numbers appear more here. We move on to full on mixed number values.
  • Quiz 3 - Don't forget to carry your values over to the fractions. Remember estimate your answer first and then work on the precise answer.

Why Is Estimating Fraction Operations So Helpful?

In our complex world we constantly encountering values of all different kinds. A vital portion of the number sense is understanding the concept of value with fractions. The main concept that students should focus on, when it comes to this topic, is whether the value is closer to one or zero. This will allow you to quickly estimate values. Especially when it comes to processing addition and subtraction operations. As we adapt this skill to real world problem, we may just want to get in the habit of estimating by always going up a full whole number, regardless if the fraction is closer to zero or a whole value of one. While precision is one thing, accommodating the scenario is a whole different topic altogether. Think of a situation where you have cases of fruit like strawberries, grapes, and peaches. Some of the cases are partial full, creating a fractional portion. If you need to move those cases of fruit into new containers, you would need to estimate up to accommodate a situation like this.