Mixed Number Subtraction: Mastering Unlike Denominators

Mathematics Grades 5th Grade 6:02 Video
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Lesson Description

Learn how to confidently subtract mixed numbers with unlike denominators using Mr. J's easy-to-follow method. This lesson reinforces fraction concepts and subtraction skills.

Video Resource

Subtracting Mixed Numbers (Unlike Denominators) | Math with Mr. J

Math with Mr. J

Duration: 6:02
Watch on YouTube

Key Concepts

  • Mixed Numbers
  • Unlike Denominators
  • Equivalent Fractions
  • Subtraction

Learning Objectives

  • Students will be able to find a common denominator for two or more fractions.
  • Students will be able to subtract mixed numbers with unlike denominators by finding equivalent fractions.
  • Students will be able to simplify their answers to the lowest term.

Educator Instructions

  • Introduction (5 mins)
    Begin by reviewing what mixed numbers and denominators are. Briefly discuss why we need a common denominator to subtract fractions. Introduce the video 'Subtracting Mixed Numbers (Unlike Denominators) | Math with Mr. J'.
  • Video Viewing (10 mins)
    Play the video. Encourage students to take notes on the steps Mr. J outlines for subtracting mixed numbers with unlike denominators.
  • Guided Practice (15 mins)
    Work through example problems on the board, following Mr. J's method. Ask students to participate by identifying common denominators and performing the subtraction steps. Start with simpler examples and gradually increase the difficulty.
  • Independent Practice (15 mins)
    Provide students with worksheets containing subtraction problems with mixed numbers and unlike denominators. Have them work individually and offer assistance as needed.
  • Wrap-up & Review (5 mins)
    Review the key steps for subtracting mixed numbers with unlike denominators. Address any remaining questions or areas of confusion. Preview the upcoming topic.

Interactive Exercises

  • Fraction Frenzy
    Divide the class into teams. Present a subtraction problem with mixed numbers. Each team races to find the correct answer. The first team with the correct answer gets a point. The team with the most points wins.
  • Online Practice
    Use an online interactive website or app to create interactive practice problems.

Discussion Questions

  • Why is it important to have a common denominator when subtracting fractions?
  • What are some strategies for finding the least common denominator?
  • How can you check your work to make sure your answer is correct?

Skills Developed

  • Finding Common Denominators
  • Subtracting Fractions
  • Problem-Solving
  • Critical Thinking

Multiple Choice Questions

Question 1:

What is the first step in subtracting mixed numbers with unlike denominators?

Correct Answer: Find a common denominator

Question 2:

What is the common denominator for 1/3 and 1/4?

Correct Answer: 12

Question 3:

What is 4 1/2 - 2 1/4?

Correct Answer: 2 1/4

Question 4:

To subtract mixed numbers, the denominators must be:

Correct Answer: The same

Question 5:

What is the equivalent fraction of 1/2 with a denominator of 6?

Correct Answer: 3/6

Question 6:

When subtracting mixed numbers, if the fraction you are subtracting is larger than the one you're starting with, you must:

Correct Answer: Borrow from the whole number

Question 7:

What is 5 2/3 - 1 1/6?

Correct Answer: 4 1/2

Question 8:

Simplifying a fraction means:

Correct Answer: Dividing the numerator and denominator by the same number

Question 9:

Which of the following is a mixed number?

Correct Answer: 3 1/2

Question 10:

What is 3 1/5 - 1 2/5?

Correct Answer: 1 4/5

Fill in the Blank Questions

Question 1:

A number with a whole number and a fraction is called a __________ __________.

Correct Answer: mixed number

Question 2:

The bottom number of a fraction is called the __________.

Correct Answer: denominator

Question 3:

Fractions that have the same value are called __________ fractions.

Correct Answer: equivalent

Question 4:

Before subtracting fractions, you need to find a __________ __________.

Correct Answer: common denominator

Question 5:

The top number of a fraction is called the __________.

Correct Answer: numerator

Question 6:

4 2/5 - 1 1/5 = __________.

Correct Answer: 3 1/5

Question 7:

When you make a fraction smaller, it is called __________.

Correct Answer: simplifying

Question 8:

3/6 is the same as 1/__________.

Correct Answer: 2

Question 9:

4 1/2 - 2 = __________.

Correct Answer: 2 1/2

Question 10:

To find a common denominator, find the __________ __________ __________ of the two denominators.

Correct Answer: least common multiple

Educational Standards

5.N.3:Add and subtract fractions with like and unlike denominators, mixed numbers, and decimals to solve real-world and mathematical problems. 5.N.3.3:Add and subtract fractions with like and unlike denominators, mixed numbers, and decimals, involving money, measurement, geometry, and data. Use various models and efficient strategies, including but not limited to standard algorithms. 5.N.3.1:Estimate sums and differences of fractions with like and unlike denominators, mixed numbers, and decimals to assess the reasonableness of the results.

Teaching Materials

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