## Dividing Mixed Numbers Algorithm.png - Section 2: Developing an Algorithm

# Dividing Mixed Numbers Algorithm

Lesson 5 of 10

## Objective: SWBAT develop the algorithm for dividing mixed numbers.

*50 minutes*

#### Do Now

*15 min*

Students often have difficulty with word problems and are intimidated by them. Students have worked on different strategies for solving word problems, such as draw a picture, highlight important information, and work backwards. For this Do Now problem, I'm introducing a fun way of having students visualize the situation in the problem, acting it out.

I will give one group the Division Problem Acting Out.docx Worksheet and assign them roles. They should read the problem and discuss how they will act it out. I will explain to them that they don't have to speak during their "play", they can simply act it out with motions. They will have 2 - 3 minutes to present their "play" for the class.

When the group is finished presenting, students will be instructed to complete the Do Now problem.

**Do Now**:

Janna brings peanuts to be shared equally by her and her 3 friends. If they share ^{1}/_{4} pound of peanuts, how much of a pound will each student get?

After a few minutes, I will ask students to share their reasoning, work, and answers.

*Did the presentation help? How?*

*What operation did you use? *

#### Resources

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#### Developing an Algorithm

*10 min*

Students have previously developed an algorithm for multiplying mixed numbers and dividing fractions. This lesson will rely heavily on students prior knowledge to develop an algorithm for dividing mixed numbers.

I will introduce the below example to students.

Example 1

20 ½ ¸ 2 ^{2}/_{3}

*When we multiplied with mixed numbers, what did we do first?*

- Students should remember that we changed the mixed numbers to improper fractions.

*How did we divide fractions?*

- Students have the strategy of Keep, Change, Reciprocal.

This leads us to the Dividing Mixed Numbers Algorithm.png for dividing mixed numbers.

I will model another example with students to ensure that they use the algorithm correctly.

Example 2

2 ^{1}/_{3} ¸ 1 ^{1}/_{3} =

#### Resources

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#### Group Practice

*20 min*

Since students tend to miss a step when dividing mixed numbers, they will work with their group to solve the problems below. I will encourage discussion among students and emphasize that they should "check in" with their group as they work. For this lesson students have been grouped by math level, based on a previous assessment.

Students will be given 10 minutes to complete the Group Work Problems.png. As students are working I will circulate, but focus more on the lower level math groups.

After about 10 minutes, I will randomly select students to present their work to the class.

#### Resources

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#### Exit Ticket

*5 min*

To assess students' understanding of dividing mixed numbers, they will complete an exit ticket. They will have 5 minutes to complete the problem below. The exit tickets will be used to help me determine student groups and future lessons.

**Exit Ticket**

8^{3}/_{7} ¸ 1^{4}/_{5} =

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##### Similar Lessons

Environment: Urban

Environment: Urban

Environment: Urban

- UNIT 1: First Week of School
- UNIT 2: Properties of Math
- UNIT 3: Divisibility Rules
- UNIT 4: Factors and Multiples
- UNIT 5: Introduction to Fractions
- UNIT 6: Adding and Subtracting Fractions
- UNIT 7: Multiplying and Dividing Fractions
- UNIT 8: Algorithms and Decimal Operations
- UNIT 9: Multi-Unit Summative Assessments
- UNIT 10: Rational Numbers
- UNIT 11: Equivalent Ratios
- UNIT 12: Unit Rate
- UNIT 13: Fractions, Decimals, and Percents
- UNIT 14: Algebra
- UNIT 15: Geometry

- LESSON 1: Multiplying Fractions
- LESSON 2: Creating Word Problems for Multiplying Fractions
- LESSON 3: Multiplying Mixed Numbers
- LESSON 4: Dividing Fractions
- LESSON 5: Dividing Mixed Numbers Algorithm
- LESSON 6: Operations with Fractions Review
- LESSON 7: Fractions Word Problems Review
- LESSON 8: Number Sense Unit Exam
- LESSON 9: Test Corrections
- LESSON 10: Fractions Unit Project