Distribute to Multiply
Students will be able to solve multiplication problems using the Distributive Property of Multiplication.
Introduction (15 minutes)
- Invite your students to come to the class meeting area and bring their math journals and a pencil.
- Tell them to place their supplies on the floor next to them.
- Tell the students that today they're going to learn a strategy for solving 1 X 1, 1 X 2, and 2 X 2 multiplication problems. Write the word “Distribute” on the board.
- Let the students know that to distribute means to divide and dispense in portions.
- On the board write the following words next to the term "Distribute," “Distributive Property of Multiplication."
- Tell them that the Distributive Property of Multiplication works as follows, while writing the following on the board: "If a × (b + c) = a × b + a × c, then × distributes over +."
Explicit Instruction/Teacher Modeling (15 minutes)
- Direct the students’ attention to the board.
- Write a 1 X 1, 1 X 2, or 2 X 2 multiplication problem on the board. For example 6 X 12.
- Tell the students that the first thing we want to do is to choose the factor they consider hard and distribute it into two portions that are easier for them to work with.
- Ask the students which factor they would like to break down to make the expression easier to solve. Encourage the students to choose the 12 as it is larger and often more difficult for students to work with.
- Let the students know that when we distribute the 12 into easier factors we are breaking it down into two numbers that, when added together, sum to 12. In this case, our numbers could be 2+10, 5+7, or 6+6 just to name a few.
- Choose one of the suggested possibilities, we'll use 2+10, and write the following, based on the Distributive Property of Multiplication, on the board: "6 (2 + 10) ="
- Then, solve the problem on the board and with input from the students: "(6 X 2)+(6 X 10) = 12 + 60 = 72"
Guided Practice/Interactive Modeling (10 minutes)
- Put another problem on the board, similar to the one just completed.
- Tell the student to pick up their supplies and write the problem down.
- Ask for volunteers to raise their hands and share with the class the steps involved based on the problem just completed on the board.
- Give the students time to solve the problem.
- Have your students volunteer the steps to solving the problem as you write them on the board.
- When the problem is done, review it with the class for accuracy. Make sure everyone has the problem written down as a reference for completing their assignment during independent work time.
Independent Working Time (15 minutes)
- Send the students back to their seats.
- Pass out the Distributive Property worksheet.
- Walk around and observe the students as they work on completing the assignment.
- Monitor the students as they work, making sure the problems are done correctly.
- During this time ask questions of the students to make sure they understand the concept of using the Distributive Property of Multiplication to solve multiplication problems that have factors that are considered harder to work with.
- Answer questions and offer help where needed.
- Enrichment: Give advanced students harder problems to solve, such as 2X2s, like 12 X 18.
- Support: Observe and monitor these students more closely. Perhaps get involved in helping the students solve the problems. You may want to fall back on easier problems like 1X1s, such as 4 X 8 to solve. Manipulatives can also be used. Students who are having trouble finding the factors of their chosen number can be given the It's Distributed! worksheet to complete during independent work time.
Assessment (10 minutes)
- The students will be assessed based on the comments and feedback received during the lesson about the assignment problems.
- They will also be assessed based on the results of the completed problems assigned.
Review and Closing (10 minutes)
- Bring the students back to the class meeting area.
- Ask for volunteers to share their answers and work for the problems assigned.
- As the problems are reviewed in front of the class, the students will check their answers for accuracy.
- Ask the class if there are any questions or comments on using the Distributive Property of Multiplication to solve multiplication problems.