Today's Problem of the Day:
Look at these trees. Compare their height.
For this Problem of the Day, I include two pictures of trees. The trees are movable.
I have one student answer this question, and explain his or her thinking. If the student does not do it, I encourage the student to move the trees to ensure that he or she has enough information to compare the height of the two trees. I am looking for the student to line up the trees on bottom so that the difference in height is easily seen. I am also looking for students to use the words taller and shorter as the comparison of height is explained.
I start this lesson by handing out a Space Mat to each student and having them take it back to their seat. This mat is available in color and black and white. I use the same mats for introducing addition and subtraction, so I print them in color, put them in plastic sleeves and collect them at the end of the lesson to save for the subtraction unit. I put one copy on the document camera and project it on the SMART board so that I can model for all of the students to see.
I also give each student a train of 10 counting cubes. I have the cubes connected into trains ahead of time so that they are counted out and easy for the students to carry back to their seats. I tell students that when they get back to their seats they need to take the cubes apart, lay them beside their paper and then put their hands on their head.
Today I am going to tell you some stories. Each story ends with a question. We are going to use the cubes to answer the question at the end of each story. Stories like this that include a math problem are called word problems. While I tell you the story, use the cubes to show what is happening in the story. See it here.
I say the following word problems aloud. As I say them, I model on my mat using the cubes and have the students model the problem on their mats. I ask for a student to orally give me the answer by raising a quiet hand. We do not write down anything during today's lesson. I want the students to focus on listening to the problem and using the cubes to find the answer. The process is just as important as whether the students get the correct answer. The students need to use several of the mathematical practices to do this. They need to make sense of the problem and engage in finding the answer (MP1). They need to use the cubes to model the problem (MP4), and they need to use the cubes as math tools (MP5). At this level, cubes and other manipulatives are math tools that students need to learn to use appropriately to solve problems.
Two rocket ships are on the moon. Three more land. How many rocket ships are on the moon?
There are four aliens flying in space. Two more come to fly. How many aliens are flying in space?
One astronaut is walking on the moon. Two more astronauts join him. How many astronauts are on the moon?
Five aliens are having a party. They call five more friends to come to the party. How many aliens are at the party now?
Four rocket ships are in space. Three rocket ships are on the moon. How many rocket ships are there all together?
Six astronauts are collecting moon rocks. Three astronauts are still in the spaceship. How many astronauts are there all together?
When we are finished, I ask each student to put their cubes back together into a train. They need to count and make sure that they have 10. They then need to make a pile of papers and cube trains in the middle of their table. I select one student to collect the papers and another student to collect the cube trains. When students are finished I call one representative from each table to come back and get the center for their table. All students start their center at the same time today.
The centers for this week are:
I quickly circulate to make sure students are engaged and do not have any questions about how to complete the centers.
Today I am working with the students at the counting bears addition center and the addition sports balls center. These two centers are giving the students a lot of difficultly because we are still early in our addition unit.
Prior to clean up, I check in with the other tables to see how the centers are going. My students have been struggling with getting cleaned up quickly and quietly after centers. Lately I have been using counting down from 20 slowly instead of a clean up song. Counting backwards is as critical as counting up. Students need to be able to know the number that comes before, as well as after, any given number (w/i 10, w/i 20, etc.). Counting back is a critical strategy for subtraction.
The students like to count backwards with me as they clean up and I can lengthen or reduce the clean up time based on how students are doing and how much time we have.
To close, I put the space mat on the document camera a project it on the SMART Board and have that student show an addition word problem and explain their work. I mention positive things noticed during centers as well as something that needs to be better next time.
I review what we did during our whole group lesson. "Today we learned about solving problems that come from a story. These are called word problems. Tomorrow we will be continuing to work on word problems."