Mastering Division Involving Decimal Quantities

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Objective

Students will be able to fluently divide decimal quantities and apply this knowledge to real world situations.

Big Idea

My Mission is Decimal Division: Mastering division using decimal quantities.

Curriculum Reinforcer

5 minutes

Students will practice dividing with multi-digit quantities.

1. 736 divided by 8 (Answer: 92)

2. 7, 814 divided by 19 (Answer: 411 R5)

3. Zach bought two new jet skis for $15,480. He will make equal payments. How much will his payments be? (Answer: $430.00)

I am looking to see that students are able to line up their quotient properly when dividing and that they are following all steps of the division algorithm.

Engagement

5 minutes

Students will participate in a learning Activity:

Students will be put into groups of four. Using money and change, students will divide currency evenly among their group members. The amounts that they will divide are $6.00, $2.40, $10.00, and $7.20. Students will write their answers on chart paper. Their solution should include a visual representation. The students will present their solutions to the class by taking their chart paper to the front of the class an posting it on the board for everyone to see.

Activity #2:

In this activity, students will determine how many coins are in a specific amount of money. The amount of money is listed below:

  1. How many quarters are in $5.25?
  2. How many nickels are in $1.50?
  3. How many dimes are in $12.30?

Instruction & Teacher Modeling

10 minutes

I will use the opening exercises as a segue into instruction. During instruction, I will demonstrate to my students how each problem presented in the opening exercise is a division problem with decimal quantities. I will solve each problem presented in the opening using two methods. First, I will use repeated subtraction to show students how dividing with decimals is similar to dividing with whole numbers. Then, I will solve the problems using the standard algorithm. 

At this time, my students should be actively engaged and taking notes.

 

Try It Out

10 minutes

Students will complete five problems for guided practice that involve dividing with decimal quantities. During guided practice, I will take the time to answer questions and clear up misconceptions. One common mistake that students make when dividing with decimal quantities is not placing the decimal in the correct place in the quotient. This is an error that I will be looking for along with not lining up the digits in the quotient properly with the digits in the dividend.

Independent Exploration

20 minutes

Students will complete problems involving dividing decimal quantities on their own. The problems that they will be solving will be word problems. For this reason, I will stipulate that the keywords, phrases, and important values must be marked before solving the problem. I will travel the room and answer questions that arise from my students.

Closing Summary

20 minutes

Selected students will present their answers to the independent practice by placing their work under the document camera. They will present what they chose to underline as keywords and/or phrases. They will explain why they chose to underline those particular keywords/phrases by telling us what those keywords/phrases meant. They will then go through the algorithm for dividing decimal quantities step by step.

During this time, their fellow students and I will be critiquing their work. We will ask questions and give feedback to the presenting student.