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 two-sided 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 two-sided counters to solve the first set of problems.
With a partner, the student will use the two-sided counters to find the sum and flip the addends to show the commutative property with each problem. Each group will do 3-4 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.