Fractions Fun

Grade Level

5th Grade

Duration

30 minutes

Common Core Standards

CCSS.MATH.CONTENT.5.NF.A.1: 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.
CCSS.MATH.CONTENT.5.NF.A.2: Solve word problems involving addition and subtraction of fractions referring to the same whole and having like denominators or unlike denominators.

Learning Objectives

By the end of this lesson, students will be able to:

Understand how to find a common denominator for two fractions with unlike denominators.
Add and subtract fractions with unlike denominators using equivalent fractions.
Solve simple word problems involving addition and subtraction of fractions with unlike denominators.

Materials Needed

Whiteboard and markers
Fraction visual aids (fraction circles and bars)
Worksheet (included at the end)
Pencil and eraser for each student

Lesson Outline

1. Introduction to Fractions with Unlike Denominators (5 minutes)

Visual: Use fraction circles or bars displayed on the board/projector.

Show (\frac{1}{3}) and (\frac{1}{4}) represented as fraction circles or bars.
Ask students: Can we add these fractions as they are? Why or why not?

Explain: Fractions must have the same denominator to add or subtract directly. We will learn how to find a common denominator.

2. Finding a Common Denominator (7 minutes)

Visual Aid: Draw fraction bars on the board.

Model finding the least common denominator (LCD) between denominators 3 and 4.
- Show multiples of 3: 3, 6, 9, 12
- Show multiples of 4: 4, 8, 12
- LCD = 12
Convert (\frac{1}{3}) and (\frac{1}{4}) to equivalent fractions with denominator 12:
- (\frac{1}{3} = \frac{4}{12})
- (\frac{1}{4} = \frac{3}{12})

Check for understanding questions:

What is the least common denominator of 5 and 10?
Can you show me how to rewrite (\frac{2}{5}) as a fraction with denominator 10?

3. Adding and Subtracting Fractions (8 minutes)

Visual: Use fraction bars to show the process.

Add (\frac{4}{12} + \frac{3}{12} = \frac{7}{12})
Subtract (\frac{4}{12} - \frac{3}{12} = \frac{1}{12})
Remind students not to add/subtract denominators, only numerators.

Interactive Practice (with 3 examples on board):

(\frac{2}{5} + \frac{1}{10})
(\frac{3}{8} - \frac{1}{4})
(\frac{5}{6} - \frac{1}{3})

Have volunteers come up and work through one of the examples with visual aids.

4. Word Problem Activity (5 minutes)

Example Problem:

Sarah baked (\frac{3}{4}) of a cake. She gave (\frac{1}{3}) of the cake to her friends. How much cake does Sarah have left?

Guide students to find the LCD (12), convert fractions, subtract, and then simplify if needed.

Ask: What strategies did you use to solve the problem? Why is finding the common denominator important here?

5. Worksheet & Independent Practice (5 minutes)

Hand out the worksheet with 4 problems:

(\frac{1}{3} + \frac{1}{6} = ?)
(\frac{3}{5} - \frac{1}{10} = ?)
( \frac{2}{4} + \frac{1}{8} = ?)
Word problem: John drank (\frac{2}{3}) of a glass of juice and then another (\frac{1}{4}). How much juice did he drink in total?

Encourage: Try to draw visual models if you need help.

Assessment & Review

Quick exit ticket: Write the answer for (\frac{5}{6} - \frac{1}{4}).
Review answers as a group before students leave.
Check worksheet for understanding and address any common errors in the next lesson.

Visuals Summary

Fraction Types	Visual Ideas
Fraction circles	Colorful pie charts
Fraction bars	Rectangular bars partitioned
LCD multiples table	Chart showing multiples
Step-by-step drawing	Converting fractions

Worksheet: Adding and Subtracting Fractions

Name: ___________________ Date: ___________

(\frac{1}{3} + \frac{1}{6} = )
(\frac{3}{5} - \frac{1}{10} = )
(\frac{2}{4} + \frac{1}{8} = )
John drank (\frac{2}{3}) of a glass of juice and then another (\frac{1}{4}). How much juice did he drink in total?

Thank you for making fractions fun!

Teaching Instructions