I ask the students to each grab 8 tiles or cubes and sit in front of the Smart Board. Using the Quick Flash routine, established in a previous lesson, flash the cube card G. Ask the students to determine the total number of cubes for the flash and share their strategy for for finding the total before they recreate the image. Then do the same thing with card H.
*The cards needed for this activity can be found in the Warm Up section of the linked lesson.
It is expected that sound mathematicians can Make sense of problems and persevere in solving them. "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)." The following assessment will allow you to assess how students are doing as they progress toward this proficiency.
"I want to see how well you are doing with your ability to solve addition number stories. Today, I am going to ask you solve a story problem. Your job is to decide what is going on in the story, choose a just right strategy that you can use to solve the story, and then show me your thinking on your paper."
"I am going to read the story to you twice. I want you to shut your eyes and create a picture of the story in your mind as I read it aloud. I will read the story twice."
I want to reinforce the visualization that I have been establishing with them all year long. Reading the problem twice will allow them to work on seeing the action of what is going on in the problem.
"Our class is making snowballs for our igloo. The boys made 8 snowballs. The girls made 5 more. How many snowballs do we have for our igloo now?"
"I now want you to go find a place on your own to solve this problem. Remember to show your thinking on your paper."
I allow the students to find a spot on their own. I am comfortable with kids working on the floor, at tables, or anywhere else. You need to decide what works for you.
*The problem is located in the section's resource.
The students will have a choice of a variety of addition and subtraction activities. All but one of them has been introduced in previous lessons.
1. Teen Take Away: This game is for your students who are demonstrating fluency with their facts 1-10. I have included a video of students demonstrating how to play the game. You can use a deck of playing cards. I use the Ten Frame Cards that I order from another company. The game works as follows: Each player takes a 10 card. The other ten cards are removed from the deck and set aside. The remaining cards are divided into two piles (1-4) and (5-9). A student draws a card from the 1-4 pile and adds that number to their ten card. Then they pull a card from the 5-9 pile and subtract that number from the combined number. The second player then repeats this process. Each player then records their equation on a piece of paper and then starts a new round.
2. Story Problems: The students should continue working on the the problems they started two lessons ago. For those who finish and are ready for more challenging problems. It is expected that, by the end of the year, 1st grade students can "use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem (CCSS.Math.Content.1.OA.A.1)." These problems are allowing you to gain an idea of how each student is developing with their progress toward this standard.
3. Adding Dice Dots: This activity was introduced in the lesson Addition Rendition. Go to the Center Time section of the linked lesson to see the description and the resources needed.
4. Dice Subtraction: This activity was introduced in the lesson Ideas on Subtraction. Go to the Center Time section of the linked lesson to see the description and the resources needed.
Activities 3 & 4 both have students working on addition and subtraction fluency. The Core Standards expect first graders "to relate counting to addition and subtraction and add/subtract within 20, demonstrating fluency for subtraction within 10 (CCSS.Math.Content.1.OA.C.5 & CCSS.Math.Content.1.OA.C.6)." These two activities allow for the opportunity to work on these skills and take steps toward fluency.
I will end the session with a discussion about subtraction. I want students to see that subtracting the same difference regardless of context (dots, tiles, cubes, etc.)
I call the students over to the carpet area. "Today I want to talk about some ways you've been using to subtract. We've played subtraction games like Dice Subtraction, Subtraction Bingo, and we solved subtraction Story Problems."
"Let's pretend we're playing Dice Subtraction. I roll a 10 on the number cube and a 6 on the dot die. Who can tell us how they would figure out what 10 minus 6 is? If you have 10 and take away 6,how many are left?"
I will then ask a few students to share their strategy for folding 10-6. I will model each example on the whiteboard.
Then propose a story problem that involves 10-6 and repeat the same sharing process as you just did with the dice example.
Then finish with a 10-6 situation from Subtraction Bingo and repeat the share process again.
For some students, 10-6 is a new problem to be solved each time they see it. Some students will make the connection that 10-6 will always equal 4. Discussions like this help students with the development of their understanding of this concept.
I have included a video of one student's explanation of how she solved this equation.
I want to continue to assess the students development with identifying and writing transitional numbers as well as their ability to count up and back on the number line. This activity allows me to quickly gain a snapshot of their progress. The worksheet is attached.