## Cherries are Positive, Lemons are Negative- Part 2

### Rita Williams

#### Description

Designed to follow Cherries are Positive, Lemons are Negative, this lesson has students discover the rules for subtracting integers.

#### Objectives

The student understands and explains the effects of addition, subtraction, multiplication, and division on whole numbers, fractions, including mixed numbers, and decimals, including the inverse relationships of positive and negative numbers.

#### Materials

-Paper plates
-Aluminum foil
-Pencils
-Activity Sheet (See Associated File)
-Rubric (See Associated File)

#### Preparations

1. Make sure you understand the directions the students are going to have to follow.
2. Gather materials. (Cherry and lemon heads can usually be found at Dollar stores. Also, you may choose to use red and yellow construction paper pieces.)
3. Wrap 10 lemon heads and 10 cherry heads in aluminum foil for each pair of students.
5. Make copies of the Activity Sheet and Rubric for each student.

#### Procedures

1. This lesson was designed to follow Cherries are Positive, Lemons are Negative, so have the students recall what they discovered during that activity. (See Weblinks)

2. Tell the students that they are now going to discover the rules for subtracting integers by using cherry heads and lemon heads.

3. Put students in pairs. Review your rules on how to be a cooperative worker. Encourage them to work cooperatively with each other throughout the activity. Let them know they will be assessed on how they interact with each other.

4. Distribute the Activity Sheet and Rubric to each student. (See Associated File) Review the Rubric with the students and answer any questions.

5. Review the 3 statements at the top of the first page on the Activity Sheet. Make sure they understand that positive 1 and negative 1 cancel each other out.

6. Distribute one aluminum foil package of 10 cherry heads and 10 lemon heads and one paper plate to each pair. Make sure they all have pencils.

7. Instruct them to complete the Activity Sheet. (The directions on the Activity Sheet are very detailed, so it is not necessary for you to walk them through the entire activity. Just be available for questions.)

8. Facilitate a discussion on the rules they created for subtracting integers. (You might have to use a second day to do this, depending on how quickly the students complete the activity.)

9. Make sure they leave the class knowing the correct rules.

10. Collect their Activity Sheets and assess them with the Rubric.

#### Assessments

Each student completes the attached Activity Sheet. The Activity Sheet is assessed using the attached Rubric. The Rubric only assesses the student's understanding and explanation of the effects of subtracting positive and negative integers; it does not assess the entire benchmark.

#### Extensions

1. Modification: Red and yellow construction paper pieces can be used in place of cherry and lemon heads.
2. Extension: After this lesson, students are ready to learn the paper and pencil method of subtracting integers.