In Chapter 1, we learned several mental math strategies for adding numbers. In today’s lesson, we will learn the Commutative Property of Addition to help us understand that we can add numbers in any order. we do not need to know the name of the property, but should understand the essence of it. we will practice applying this property to find sums.
In Chapter 1, we learned several mental math strategies for adding numbers. In today’s lesson, we will learn the Commutative Property of Addition to help us understand that we can add numbers in any order. we do not need to know the name of the property, but should understand the essence of it. we will practice applying this property to find sums.
Math4u grade 2 first term
ماث فور يو جريد 2
math grade 2 first term
math grade 2 first term
شرح دروس ماث جريد 2 الترم الاول المنهج الجديد بأسلوب سهل وبسيط
شرح دروس ماث جريد 2 الترم الاول المنهج الجديد بأسلوب سهل وبسيط
Mathematics Teacher`s Guide primary 2
Math primary 2 first term lesson 31
Learn (40 minutes)
Learn (40 minutes)
Directions
Directions
1.TEACHER SAY: We have learned so many mental math strategies to help us add numbers together. Let’s review our list together.
STUDENTS DO: Review Mental Math Strategies poster with the teacher.
TEACHER SAY: Great work. Today we are going to use these strategies to learn a new property of addition. Let's start with some easier numbers.
2.TEACHER DO: Write 4 + 5 on the board.
TEACHER SAY: Turn to your Shoulder Partner and tell each other what you think is the answer to this addition problem. When you share your answer, tell your partner the mental math strategy you used to solve it.
TEACHER DO: Give partners about 30 seconds to solve and discuss, and then use an Attention Getting Signal to bring the group back together. Call on students to answer the problem and share the mental math strategies they used to solve.
STUDENTS DO: Selected students share the mental math strategies they used.
TEACHER SAY: Fantastic. _____ (Student’s name) used the _____ (name of mental math strategy) to get the sum of 9. Let's see what happens when we switch the addends, or the two numbers we are adding, around.
TEACHER DO: Write 5 + 4 on the board.
TEACHER SAY: Think for a moment: When we add these numbers together, what will be the sum? How are these two problems different? How are they alike? Discuss this with your Shoulder Partner.
STUDENTS DO: Turn and discuss their thinking with their Shoulder Partner.
TEACHER DO: Call on a few pairs of students to share the answer and discuss their thoughts.
STUDENTS DO: Selected partners share the answer and discuss their thinking.
3.TEACHER SAY: I wonder if this works when we add larger numbers together. Let’s try this one together.
TEACHER DO: Write 12 + 7 = _____ on the board.
TEACHER SAY: We learned that it is easier to start with the larger addend when adding in our heads, so let’s start with 12 and count on. Count on with me.
TEACHER DO: Model counting on to solve 12 + 7 by starting at 12 and then counting on 7 more (to 19).
STUDENTS DO: Count aloud with the teacher.
TEACHER DO: Write the answer on the board (12 + 7 = 19).
TEACHER SAY: So, 12 + 7 = 19. What if we switch the addends around? Will we get the same answer?
TEACHER DO: Write 7 + 12 = _____ on the board.
TEACHER SAY: Let’s use the 120 Chart to add 7 and 12. Help me count on.
TEACHER DO: Using the 120 Chart, start at 7 and count on 12 spaces to 19.
STUDENTS DO: Count aloud with the teacher.
TEACHER DO: Write the answer on the board (7 + 12 = 19).
TEACHER SAY: Did we get the same answer?
STUDENTS DO: Respond together.
TEACHER SAY: What does that tell us about addition problems? Does the order of the addends in an addition problem matter? Turn and Talk to your Shoulder Partner and share your thinking. When you are ready to share your thinking with the class, give me a Thumbs Up.
STUDENTS DO: Turn and Talk to Shoulder Partner to share their thinking about the order of addends. Give a Thumbs Up when ready. Selected students share their thinking.
TEACHER DO: Listen to students’ answers. If no students share that the order of the addends in an addition problem does not matter or that you will get the same answer if the addends are switched, explain the concept to students. Use additional examples to build understanding. When students are ready, provide time for them to practice the concept.
4.TEACHER SAY: Let’s try a few of these in our student book. Please take out your book and turn to page Lesson 31: Apply.
STUDENTS DO: Take out student book and turn to page Lesson 31: Apply.
TEACHER SAY: On this page, you will see several addition problems. You will solve the problem on the left side. Th en you will rewrite the problem by switching the addends on the right side. Th en you will solve the new problem.
TEACHER DO: If students need additional support, do the first Apply problem together. Walk around the room and monitor students’ work, offering help as needed. Ask students which mental math strategy or strategies they used to solve the problems.
