Collecting data - math grade 2 - lesson 8

STUDENTS DO: Raise hand to volunteer. Selected students answer the question.

TEACHER SAY: Yes, sum is what we call the answer when we add two or more numbers together. Today we will be rolling two dice and adding the numbers together. Then we will record the sum on a bar graph to see which sum we rolled the most. Open your student book to page Lesson 8: Apply.

STUDENTS DO: Open student book to the page for Lesson 8.

TEACHER SAY: On the board there is a graph just like the one you have in your student book. This graph has a title: Which Sum Is Rolled the Most? These numbers are all the sums we could possibly get if we roll two dice and add them together. The vertical side of the graph is labeled Number of Rolls. Each line moving up the graph represents 1 roll (point). Along the horizontal side (point), we see the numbers 2 to 12. These numbers are all the sums we could possibly get if we roll two dice and add them together. The label is Sums. Why is there no column for a sum of 1? Think for a minute and then raise your hand to share.

STUDENTS DO: Think for a minute and then raise hand to volunteer. Selected students share their thinking.

Note to the Teacher: If no student shares that you cannot get a sum of 1 with two dice, be sure to explain.

2.TEACHER SAY: Good. Let’s see how we will make this graph. I am going to model a couple of rolls for you. Then you and your Shoulder Partner will share a set of dice and make your own graph of your rolls.

First, I will roll the dice. I rolled a _____ and a _____. I will add those together: _____ + _____ = _____, so I color in the first box above that sum.

TEACHER DO: Model rolling the dice and coloring in one box. Example: 3 + 4 = 7, so color in the first box for 7. If necessary, explain why you are starting with the bottom box instead of the top box. Repeat for two more rolls.

TEACHER SAY: When you play, you will continue to roll and find the sum of the two dice until one of the sums reaches the top of your graph. That is the “winning” sum that answers the question in our graph title. Then you will stop. Remember that even though you are sharing a pair of dice and helping each other add, you should each complete the graph in your own student book. I have a question for you: Will we all have the same answer? Why or why not? Talk to your Shoulder Partner, and then I want to hear your thinking.

STUDENTS DO: Talk to Shoulder Partner about the teacher’s question. Selected students share their thinking with the group.

TEACHER DO: If necessary, explain that since every pair of students is rolling a different set of dice and collecting their own data, they will not all have the same answers or graphs. Hand out two dice to each pair of students. Hand out (or have students take out) crayons.

STUDENTS DO: Play the game with Shoulder Partner: Roll the dice, work together to find the sum, and record. Continue to repeat until the teacher says stop or a sum reaches the top of the graph.

TEACHER DO: Walk around the room and observe students rolling and recording. Offer assistance where necessary and note students who are having difficulty adding the numbers or recording the data. Near the end of the Learn segment, use an Attention Getting Signal.

3.TEACHER SAY: What fun that was rolling and recording to answer the question “Which Sum Is Rolled the Most?” Bring the dice back to me and return to your seats with your student book open to the graph you just created.

STUDENTS DO: Return dice and sit down with student book open to their graph.

TEACHER SAY: Let’s see which sums were rolled the most today. Look at your graph. When I call a sum, if you rolled that sum the most and have the highest bar in that column, stand up.

TEACHER DO: Call out each sum.

STUDENTS DO: Stand up when their winning sum is called and then sit down.

TEACHER SAY: Wow. We had a lot of winners for some sums and only a few for others. Everyone’s graph looks different, since you all had different data, or information, that you added to your bar graph. We can find out different things from each of your graphs and ask different questions. Keep out your student books with your graphs.