Adding Integers - What's the Rule?

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Objective

Students will be able to develop a mathematical rule for adding integers, and apply the rule to solve problems.

Big Idea

Can you add without integer chips or a number line? In this lesson students will brainstorm properties of integer addition problems.

Launch

5 minutes

Opener:  As students enter the room, they will immediately pick up and begin working on the opener.  Please see my instructional strategy clip for how openers work in my classroom (Instructional Strategy - Process for openers).  This method of working and going over the opener lends itself to allow students to construct viable arguments and critique the reasoning of others, which is mathematical practice 3

Learning Target:  After completion of the opener, I will address the day’s learning targets to the students.  In today’s lesson, the intended targets are, “I can develop and use a mathematical rule for adding integers.” Students will jot the learning target down in their agendas (our version of a student planner, there is a place to write the learning target for every day). 

Explore

55 minutes

Link to Prior Knowledge: Students will begin the lesson solving a few problems using modeling – either integer chips or a number line (mathematical practice 5 – using tools strategically). The problems are split into two groups – those with like signs and those with different signs. After the students use modeling to solve the problems, they will look over the questions and answers and brainstorm with their table group to come up with ideas for a rule. At this point I do not need anything concrete, I am just looking for them to offer ideas – when I added two negatives my answer is negative, or when I add a positive and a negative the signs of my answers varied, etc. I will monitor this brainstorming activity, and wrap it up as I begin to notice groups straying…This activity bring in mathematical practice 8, looking for and expressing regularity and repeated reasoning. With this topic, it is very important that students are precise when paying attention to the signs of the numbers, mathematical practice 6

Table Practice: Students will work individually for 5 minutes on the 24 integer addition problems, and then have 3 additional minutes to go over answers with their tables. I will call on students to share out answers for the problems, almost every student should get to answer one!

Summarize

5 minutes

Around the World:  To summarize this lesson, I am going to play the ever fun game of Around the World.  Using integer addition problems I have written on notecards, I will place one student next to another and show them the problem.  The first one to correctly answer moves to the next student – twist alert – if a student shouts out the wrong answer I make them wait until the other student has had at least 15 seconds to figure out and take a guess before allowing them a second try.  First student to correctly answer moves on.