Lesson Plan for Adding Integers

Goal: SWBAT add and subtract integers. Explain additive inverses. Defend why adding a negative is the same as subtracting a positive, also why subtracting a negative is adding a positive.

Developing understanding activity.

Hot and Cold Cubes

7NS:

Teacher note: Establish that one blue cube represents one degree colder or negative one degree temperature change and one red cube represents one degree hotter or positive one degree temperature change. Without any cubes in the soup that represents zero.

Anticipation for developing understanding activity

1.  Different vocabulary for additive inverses, zero pairs, opposites.

2.  May represent the condition in equation form and some may have written form.

3.  4 – (-3) students not know how to zero out the soup so that 3 blue cubes may be removed.

Hot and Cold Cubes

Directions: 1 Blue cube = 1 degree colder or -1 1 Red cube = 1 degree warmer or +1. If no cubes are in the soup than the temperature is zero.

1.  Find three ways that your soup has a temperature of 0. Diagram your solutions.

2.  Explain your solutions to question 1. Write an equation representing a solution to question 1.

3.  Find three ways that your soup has a temperature of -1. Diagram the solutions.

4.  Find three ways that your soup has a temperature of +2. Diagram your solutions.

Model each equation using your hot and cold cubes and draw the solution.

5.  5 – 2 = 3 6. 5 + (-2) = 3

7.  -3 + (-6) = -9 8. -3 – 6 = -9

9. -4 + 2 = -2 10. -4 – (-2) = -2

11.  4 - (-3) = 7 12. 4 + 3 = 7

13. – 6 – (-3)= -3 14. -6 + 3 = -3

15. 2 – 4 = -2 16. 2 + (-4) = -2

Solidify Understanding

Football

1. How is a defensive penalty like an offensive gain?

2. How is an offensive penalty like a defensive gain?

Given the equation solve and then write a sentence describing the football plays.

10 + -2 = 8 / Run for a gain of 10 and then a sack for a loss of 2. Total gain of 8 yards.
15 + 10 =
-7 + -11 =
5 + (-6) =
-4 +21 =
7 – 6 =
8 – 14 =
-4 – 3 =
-8 – 13 =
-7 – (-8) =
16 – (-9) =

Students should draw their own football field number line and model the following equations on the field. The starting point (0) is the fifty yard line.

Equation Number line drawing

5 + 2
2 – 5
5 – (-2)
5 + (-2)
-5 – (-2)
-5 + (-2)
-5 + 2
5 - 2

How is subtracting a negative like adding a positive?

How is subtracting a positive like adding a negative?

Name Date

Work with a partner. Write the addition expression shown. Then find the sum.

Inductive Reasoning

Work with a partner. Use integer counters or a number line to complete the table.

Exercise / Operation: Add or Subtract / Answer
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