Using the dot image cards in the section resource (make three copies), follow the quick image routine and flash the 4 & 3 cards. Then repeat with 5 & 2, and 2, 2, & 3. I am looking to see if students can relate 5&2 to the conversation with 4&3. I am looking for them to see the relationship with the 2,2,&3 as well.
Advanced Preparation: Using the resources in the section resource, you will need 3 game boards and one set of dot cards per team. To make a set of dot cards, you will have to make enough copies so that each set has 8 cards with two dots, 4 cards with three dots, 4 cards with four dots, and 4 cards with five dots. I would make one set and then photo copy the set and have each team cut out their own.
I gather the students in a circle on the carpet and lay out the cards face up.
"I would like you to share a way that you can make 6."
Have a few students share their combinations. When you feel everyone has the idea move forward with the explanation of the activity.
"The object of the game is to move the cards onto the game board to make combinations for each number. There will be more than one answer for each number." Once you find a combination, you can write the number combination as an equation on your own board. After you record your combination, you can clear the board and put the numbers back into the array."
There is a video clip of this introduction in the section resource.
Students pair up and play the game that was just introduced int he previous section. You will want to have extra copies of the game board sheet as needed.
While students are working, you will want to circulate and observe how students find combinations for each number. Is it random or are they counting on from one number? Are there any known facts that students have mastered? How do students do with writing equations? The CCSS want students to make sense of problems and persevere in solving them. The expectation is that mathematically proficient students start by explaining to themselves the meaning of a problem and looking for entry points to its solution (CCSS.Math.Practice.MP1). In this case, the students are looking for a number to start with and then counting on from that number.
Gather the students in a circle and write the number 12 on the white board. This was a number from their game board.
"I would like to know how you found combinations for the number 12."
As a student gives you a combination, you should draw the dots for each number he/she used. Then have them explain how the found the sum. Watch the video titled Using Known Facts to see an example of a student explaining a more in depth way of finding the sum of his dots.
Do this for several different combinations. The focus should be on the students sharing the strategy he/she used to find the sum. With the implementation of Common Core, students are expected to attend to precision by communicating precisely to others their thoughts, approaches, and thinking (CCSS.Math.Practice.MP6). In this episode, students are explaining to their peers how they found the sum of the dots. This discussion develops the relationship of counting to addition (CCSS.Math.Content.1.OA.C.5). The students are communicating with precision because they are elaborating on the strategy used to find the sum of the dots. They are not just sating an aster but rather explaining their thinking for others to learn from.
Students should complete the page Combinations. It can be found in the resource section. The Combinations Differentiated sheet should be used for those students who will still need the dots to solve three addend equations.