Total Duration: 
31 to 60 Minutes 
Materials and Resources: 
1. Pencils and crayons 2. Twosided counters 3. Math journals (one per child) 4. Dryerase board and markers for teacher 5. Bear Counters (red, blue, & green) 6. Vocabulary cards (addend, sum, commutative property, & associative property) 
Technology Resources Needed: 

Background/Preparation: 
Students must have a general understanding of number sense and adding numbers or set objects. Students also must have previously mastered the commutative property of addition. 
The teacher will display key vocabulary for this lesson: addend, sum, and commutative property. Briefly, the teacher will display/read each vocabulary card and discuss their meanings. The cards will remain on display with their meaning out beside them on the board. The teacher will review the commutative property of addition by using twosided counters. The teacher will write a few addition problems on the board like 4+2=6 and 2+4=6. Using the document camera, the teacher will model how to use the twosided counters to solve the first set of problems. With a partner, the student will use the twosided counters to find the sum and flip the addends to show the commutative property with each problem. Each group will do 34 problems. Bring the students back together and review the idea that commutative property means that the addends can be added in any order and the sum will still be the same. The teacher will also introduce the new vocabulary term to the list of math words. The teacher will write the following on the board: (a+b)+c=a+(b+c). To demonstrate this property, the teacher will ask for 6 volunteers. The teacher will say (1+2)+3=6. The teacher will group the volunteers like the problem. One student plus two students and then plus three more will equal six. Then she will ask the class what will happen if she groups those students differently. The teacher will explain that, like the commutative property, the sum will remain the same even with the addends are changed. The teacher will show an interactive flipchart. (See attached file. You will need ActivInspire Software to view the file.) In this flipchart, the students will be interactive by solving and answering questions with virtual manipulatives (linking cubes). Each letter in the associative property will be represented by a different color. The letter a will be green, the letter b will be red, and the color c will be blue. On the last slide of the flipchart, the teacher will have 3 problems for the student to solve. The students will be grouped by 3's. Each group will use bear counter in the colors green, red, and blue. The groups will work together to solve the 3 problems by using the associative property. In their math journals, the students will record their results from the 3 problems. 
Attachments: **Some files will display in a new window. Others will prompt you to download. 
Assessment Strategies 

Acceleration: 
Students may also visit the following websites for additional work with this skill:
Have student solve problems that have 3 addends. 
Intervention: 
Work individually or in small groups to help those who have trouble with adding more than two numbers together. Also, try varying the type of manipulative. Try using bears, linking cubes, straws, marbles, drawings, etc. 
View the Special Education resources for
instructional guidance in providing modifications and adaptations
for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.
