Multiplying 2-digit Numbers

Common Core Standards
Number and Operations in Base Ten: Use place value understanding and properties of operations to perform multi-digit arithmetic.
4.NBT.5 Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

Big Idea/Essential Question
The strategies for multiplying two-digit numbers are just an extension of the strategies for multiplying multi-digit numbers by a one-digit number.
How do I multiply a two-digit number by a two-digit number?

Lesson Objectives/Goals
The students will multiply two-digit numbers by two-digit numbers using a variety of strategies (area models, partial products, and the standard algorithm). All students are expected to complete independent practice activities with a minimum of 75% of problems answered correctly.

Accommodations for Individual Student Needs
• Learning Styles - Verbal/Linguistic (story problems), Logical/Mathematical (fact practice), and Interpersonal activities (cooperative learning, peer tutoring) are included throughout the lesson.
• Differentiated Instruction- Student will work with a partner during direct instruction. These partnerships are based on previously observed strengths and weaknesses as well pretest data. Each low student is partnered with a high student and on-level students are partnered with each other. Behavior was also considered when creating pairs to facilitate learning. Students with an IEP will have their assignment length modified and be allowed to use a multiplication table. Students who have shown difficulty with this material during previous lessons (or during informal assessment of this lesson) will be pulled to work with the teacher during independent practice. Students who are struggling with basic multiplication facts will be allowed to use the "array makers" when completing independent practice.
• Expectations - All students are expected to participate in direct instruction, cooperative activities, and independent practice. All students are expected to follow previously established classroom/school rules. The amount of problems that students are expected to complete differ during independent practice. At the end of this topic of instruction, the teacher expects that all students will be able to score 75% or above on the test.

Prior Knowledge
• Students have been working to memorize basic multiplication facts throughout the school year.
• Students have learned to multiply multi-digit numbers by one-digit numbers using a variety of strategies.
• Students have learned to solve word problems.
• Students have learned to use area models, partial products (an expanded algorithm) and the standard algorithm to solve two-digit by two-digit multiplication problems.

Curriculum Correlation/Real Life Application
Students will be presented with the following problems during this lesson.
There are 14 classes of students at our school. Each class has about as 21 students. How many students attend Chuckey School?
There are 24 cars in a race. Each car has a 13 person crew in the pit area. How many pit crew workers are at the race?
They will also be asked when they might need to multiply two-digit numbers in real life.

Procedure
The teacher will introduce the topic and discuss the agenda for this lesson. She will review the strategies that have been used in previous lessons.
• I Do – The teacher will demonstrate how to multiply two-digit numbers using an area model, partial products and the standard algorithm. She will think aloud during this procedure. She will also connect these three strategies by showing similarities.
• We Do-Students will work with their elbow partner to solve problems from the flipchart. They will be allowed to choose the strategy that they prefer. They must discuss their work. Students are expected to explain their thinking to their partner, construct a viable argument to settle disagreements during the problem solving process, and come to a consensus. Both students should be prepared to share their answer with the class. Students will be asked to share their problem solving strategy with the class by bringing their work to the front of the classroom and displaying it using a document camera. Partners will be expected to explain step by step the problem solving process.
• You Do – Students will solve problems from the flipchart independently using the method that he or she prefers.

Students that finish early will choose one of the problems solved during independent practice and film a short video using a camcorder. He or she will detail the problem solving strategy used and explain why they chose this strategy. These videos will be shown to the class during future lessons.

Reflection/Closure
The teacher will ask students to discuss the following with their elbow partner.
Which multiplication property is involved in all three strategies? (Distributive Property of Multplication) How do you know? (All three stratgies involve breaking apart factors to simplify the problem solving process.)
The teacher will review the “I Can” statements for this lesson and have students assess their learning.

Assessment
• Informal assessment will include teacher observation of student responses and participation during guided practice.
• Formative assessment will include grading independent practice assignments. Students are expected to complete independent practice activities with a minimum of 75% of problems answered correctly.
• Summative assessment will include a test at the end of this topic of instruction and a quarterly benchmark test.

Reteaching
This material will also be reviewed during the remaining lessons in this topic of instruction. Any misconceptions or specific types of mistakes noted during this lesson will be addressed at that time.

Ongoing Assessment
• Students will use the knowledge gained in this lesson to solve problems during the remainder of the topic of instruction as well as throughout the rest of the school year.
• This material will be included in future quarterly benchmark assessments.
• This material will be tested on the TCAP test in April 2014.

Assessment Plan for Unit
Students will take a test at the end of this topic (Multiplying Two-Digit Numbers). Students are expected to score a minimum of 75% on this test.

Materials:
Promethean Board or other Smart Board
Multiplying 2-digit Numbers by 2-digit Numbers flipchart
Document Camera
Camcorder