Videos and lessons to help Grade 5 students learn to add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators.

For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12. (In general, a/b + c/d = (ad + bc)/bd.)

Common Core: 5.NF.1

- I can find common denominators.
- I can create equivalent fractions with common denominators.
- I can add and subtract fractions including mixed numbers.

Related Topics:

Common Core for Grade 5

More Lessons for Grade 5

Activities:

Eric added 4/5 + 1/2 and wrote 5/10 as the sum. Explain to Eric why he is incorrect.

Two unlike fractions have a sum of 1, what might the two fractions be?

What two fractions might I subtract to get an answer of 2/3?

Dana added 2/3 + 3/5 and wrote 5/8 as the sum? Explain why this answer is impossible.

Lessons:

5.NF.1 - Add and Subtract Fractions with Unlike Denominators

This video explains how to add or subtract fractions with unlike denominators or different denominators. To add or subtract, you must have the same units (denominations or denominators). This is illustrated in a pictorial way with a model.

In this lesson you will learn to model the addition of fractions with different denominators by using fraction bars.

In this lesson you will learn to model the subtraction of fractions with different denominators by using fraction bars.

In this lesson you will learn to model the addition of mixed number fractions with different denominators by using area models.

Add and subtract fractions with unlike denominators--Lesson 4 of 6

In this lesson you will learn to model the subtraction of mixed number fractions with different denominators by using area models.

In this lesson you will learn how to use equivalent fractions to add unlike fractions and mixed numbers by using a number line.

Add and subtract fractions with unlike denominators--Lesson 6 of 6

In this lesson you will learn how to use equivalent fractions to subtract unlike fractions and mixed numbers by using area models.

Grade 4 / Math / Fractions

CCSS: Math.5.NF.A.1

Lesson Objective

Use decomposition to subtract fractions and mixed numbers

Add and subtract mixed numbers by grouping and renaming - 5.NF.1

In this lesson, you will learn how to add and subtract mixed numbers by grouping the problem into wholes and fractions and by renaming the sum or difference to reflect an answer in simplest form.

Subtract mixed numbers by decomposing wholes - 5.NF.1

In this lesson, you will learn how to subtract mixed numbers that require regrouping by decomposing wholes into their fractional parts.

In this lesson, you will learn how to subtract mixed numbers that require regrouping by renaming mixed numbers as equivalent improper fractions.

In this lesson, you will learn how to use the greatest Common Factor (GCF) to simplify fractions to lowest terms.

In this lesson, you will learn how to add and subtract fractions with unlike denominators by:

1) recognizing that you cannot count pieces together when the sizes of the pieces are different.

2) renaming one or both fractions to find the common denominator.

Common Denominators, Equivalent Fractions

Creating equivalent fractions using paper folding and finding common denominators using fraction circles.