LESSON: Subtracting Positive and Negative Integers
Standards: The content plan will correspond to state standards 1, bullet 1.1, 1.5, and 1.6.
Objectives:
Developing strategies for subtracting positive and negative integers
Recognize and use the concept of adding "zero pairs"
Explore using two models for subtracting integers
- A number line
- Black and red manipulatives to represent positive and negative intergers
Procedure:
Review the number line using subtraction
- Use the number line for several examples such as 9 - 5
- Discuss the movement on the number line
- Use the number line for several examples such as -11 - (-6)
- Discuss the movement on the number line
Review subtraction using the 'take away' model
- Use several examples such as 9 - 5
- Compare the movement on the number line
- Use several examples such as -11 - (-6) using the 'take away' model
- Compare the movement on the number line to the 'take away' model
Dyad
- Compare similarities and/or differences using these two models of subtraction
- Class discussion concerning the aforementioned
Task for the students
- Using the number line first present several problem such as -8 - (-10)
- Discuss the movement on the number line
- Ask the students how they would represent the same problem using the black and red manipulatives
- Dyad if needed to discuss what aspect of the problem they do/do not understand
- Class discussion of students' strategies
Closure:
- Students write concerning their observations
LESSON: Adding and Subtracting Positive and Negative Numbers
Standards: The content plan will correspond to state standards 1, bullet 1.1, 1.5, and 1.6.
Objectives:
Recognize and use the relationship of addition and subtraction as inverse operations
Solve situational problems using positive and negative integers
Students will write a situational problem and model the situation using the positive and negative manipulatives
Procedure:
Provide situational problems to groups of students
Groups are to use manipulatives to model each situation
Groups share their strategies and solutions
Make a math vocabulary web
Students write a situational problem and share the model representing the situation
Closure:
Write using one of the mathematical terms posted from the class list
