Anna Smoak Short Range Lesson Plan Title of Lesson: Multiplying Polynomials by Monomials Subject: Algebra I Grade level: 9th Teacher: Ms. Burgess Objective(s): Students will be able to multiply a monomial with a positive coefficient by a polynomial Students will be able to multiply a monomial with a negative coefficient by a polynomial Students will be able to apply the distributive property and the product of powers property to simplify expressions SCSDE Curriculum Standard(s) Addressed: EA-2.2 Apply the laws of exponents and roots to solve problems. EA-2.5 Carry out a procedure using the properties of real numbers (including commutative, associative, and distributive) to simplify expressions. EA-2.7 Carry out a procedure (including addition, subtraction, multiplication, and division by a monomial) to simplify polynomial expressions. NCTM National Curriculum Standard(s) Addressed: Algebra: Represent and analyze mathematical situations and structures using algebraic symbols (grades 9-12) Use symbolic algebra to represent and explain mathematical relationships Understand the meaning of equivalent forms of expressions, equations, inequalities, and relations Communication: Organize and consolidate their mathematical thinking through communication Communicate their mathematical thinking coherently and clearly to peers, teachers, and others Prerequisites: Students must be able to recognize as well as add and subtract monomials Students must be able to distribute a constant through a polynomial Students must be able to add, subtract, and multiply real numbers Students must able to use the process of combining like terms to simplify an expression Students must be able to apply the laws of exponents to multiply monomials Materials/Preparation: Smartboard and whiteboard will be used Powerpoint or Smart presentation will be minimized and ready for immediate use Students must have notebooks and pencils Procedures: Introductory Activity (15 minutes): o Review of the distributive property of multiplication Students will be shown the expression 3x As a class they will be asked what this expression means (“What does it mean to have 3x of something?” I will look for student responses such as “tripling x” “multiplying three times an unknown quantity”) They will then be asked, “Is there another way to write this expression without using the property of multiplication?” Students will be shown the expression 3(x+1) As a class they will be asked “What does it mean to have 3 times the quantity x+1?” ( I will ask students to interpret this in as many ways as they can think of including: providing a real life example to fit this situation and a mathematical explanation such as adding (x+1) three times, or adding (x+1) and then multiplying this value by three) They will then be asked, “Is there another way to write this expression without using the property of multiplication?” After writing the expression in expanded form I will ask students to simplify the new expression by combining like terms. Students will then be shown the expression 2(x - 3) As a class they will be asked about the meaning of this expression. (“What does it mean to have 2 times the quantity x-3 of something?”) They will then be asked, “Is there another way to write 2(x – 3) without using the property of multiplication?” After writing the expression in expanded form I will ask students to simplify the new expression by combining like terms. We will then note that we have seen that 3(x + 1) = 3x + 3 and 2(x – 3) = 2x – 6. Students will then be asked, “What property can we use to get from our original expression to our simplified expression?” (I will be looking for students to respond with the distributive property. My students take departmentalized tests and on these tests there are often multiple choice problems such as 2(x + 1) = 2x + 2 and students are required to chose the correct name for the property so I am using this opportunity to review with them for the cumulative portion of their test.) Students will then be given -2(x + 1) and will be asked to use the distributive property to simplify the expression. We will then go over this problem together and students will be able to check their work for accuracy o Review of multiplication of monomials Students will be shown the expression 32 x 34 They will then be asked to write (on their own paper) 32 without using exponents and will be prompted to expand this expression through the use of multiplication by the question “What does it mean for something to be squared?” (I will look for students to answer with responses such as “multiply the base which is 3 by itself”) They will then be asked to write 34 without using exponents. They will again be prompted by the question “What does it mean for something to be raised to the fourth power?” (I will look for student responses such as “multiply the base together 4 times”) Students will then multiply 32 x 34 using our expanded notation. Students will be asked, “What property can we use to get from our original expression to our simplified expression?” (Again I am using this as an opportunity to review the names of different properties with my students for their cumulative tests.) Instead of simply restating the rule for multiplication of monomials, students will be shown the expression (y4)(12y7) and will be asked to multiply the two monomials together. I will then ask students to discuss their different solution strategies. Students will then be given time to simplify the expression in their notes before we go over the problem as a class I will then give students time to simplify (4ab6) (7a2b3). I will walk around the room as students work on this problem. I will then ask for a student to volunteer their answer. I will then ask the class if anyone agrees/disagrees with this students’ response. We will then work through the problem on the board. Main Activity (20 minutes): o To begin I will ask students to discuss in pairs how they think 3x (2x + 5) is different from 3 (2x + 5) I will then ask for student responses for the entire class to hear o I will show students the expression 3x2 (2x2 + 5x – 1) and have them discuss in pairs how they think we could simplify this expression. I will ask for ideas about how to approach this problem—looking for students to mention distribution and properties of exponents. I will ask for other students to agree or disagree with the speaker and explain their reasoning. We will then work this problem on the board together with students offering the appropriate steps to follow as well as the answers to each step I will then have students work in groups to simplify the expression - (x – 2) + x (6x – 7) I will walk around the room and answer any questions and make sure pairs stay on task If students are having difficulty we will work the problem together on the board. However, if each pair seems to understand the new material I will ask a pair of students to present the problem on the board and justify each step to the class Students will again work in pairs to simplify 6rs(r2s - 3) and -9x (x2 + xy - 2y2) I will again walk around the room and answer any questions and make sure pairs stay on task As before, I will work through the problems on the board if students are having difficulty. If they are not I will have two different pairs present their solution and solution strategy to the problems. Closure (5 minutes): o I will present the ticket out of the door activity for today which is, “When a monomial is multiplied by a binomial, will the product always, sometimes, or never be a binomial?” Students will write their response and an explanation for their answer on a note card which will be collected at the end of class. Assessment: Students can successfully complete written in class and homework problems (included) which require students to multiply monomials (with both positive and negative coefficients) by polynomials and simplify their results Students are able to answer the questions presented in the lesson as well as provide justification for their responses Adaptations: Students have the opportunity to come in during their AE period or tutoring after school for extra assistance I have also increased the size of the font on the PowerPoint because several students in class have difficulty seeing the Smartboard Follow-up Lessons/Activities: The beginning of the next lesson will include a review of multiplying a monomial by a polynomial Students will complete homework problems for extra practice and will be given the opportunity to ask questions when they are reviewed the next day I will also make sure to review the ticket out of the door question at the beginning of the next class period Reflection: Clemson: Teaching this lesson as my individual lesson in class helped with my timing of the lesson. While I did not teach this lesson to my students at Wren, this was great practice for next semester. Even though we did not take the time to work in pairs during class, I was able to see the need for providing time for students to work together in pairs and having time to individually try problems on their own.