SWBAT find the missing parts of 8 through subtraction.

I want my students to develop fluency in subtraction and get them ready for future standards like 1.NBT.6, double digit subtraction. This can be done by providing them multiple opportunities to problem solve.

10 minutes

Each of our common core standards build on one another, not only within each grade, but after they leave us and go to the next grade. The standards are created in stair steps for second grade to build on what they learned in first grade. I want to teach in depth and really help our students achieve mastery for each standard, so they will find success at the next level.

My plan for this subtraction unit is to supply students with multiple opportunities to subtract tin different contexts. They need to know how to subtract to solve problems on a daily basis. They need to build fluency in subtraction to advance themselves and be ready for when they later try to solve double-digit subtraction, which is a rigorous expectation for 1st grade established by the Common core standard 1.NBT.6.

They need to identify how to decompose numbers to find the difference and learn that taking some away is how we solve subtraction. (1.OA.1). I believe one of the best things about the new Common core standards is the opportunities it supplies for kids to learn several strategies to reach the same goal. The standards require teachers to supply students opportunities to learn multiple strategies to solve subtraction and addition equations. It helps them develop a toolbox of ideas to use for computation.

To get them thinking about math today, I will begin by reminding my students of finding our missing parts of 6 and 7 from the day before. If you do not have any type of poster in your room showing them a list of the problems they created, now would be a good warm up to have them help you solve those problems and list them on chart paper, example 6-0=6, 6-1=5...7-0=7, 7-1=6, etc.

10 minutes

Need: 4 sheets white poster board; 2-inch wide orange dots

My goal through this lesson is for students to see the relationships between the same numbers that can be used to create addition problems and also used to create subtraction problems, depending on whether you are composing or decomposing the numbers. First graders must learn of the relationship between addition and subtraction to develop standard 1.OA.B.4; understand subtraction as an un-known addend problem. It is especially helpful to use different tools/manipulatives to create problems, so they can see the variety in their life and how math can occur.

Take the 4 sheets of white poster board and cut them in half. Next, use orange dots cut from construction paper to create the number patterns.

During math instruction it is common to teach them that they can find patterns everywhere, but lessons don't always teach that numbers are everywhere also. Look at the resource section and view the life-size dominoes I made from poster board. I will use these to present missing parts of 8.

Today, we are using super large dominoes to find our parts of 8 that are missing, see the pictures in the resource section. I will tell them we are looking for the missing part of 8 today. I will hold up a domino and have them help me count what we can see. We will write a number sentence and solve to find out what is missing for each domino. This helps them to see the structure of the problem and how to use the domino as a mathematical tool to find what is missing.

- I will encourage them to use their fingers to show me the 8 and then take away the dots we do see on the domino.
- Also, I will ask them to think what could be added to the known number to equal 8 as our total.

20 minutes

I love the game of Scoot because it supplies them so many problems to practice which builds fluency (1.OA.6), yet they do not realize they have worked 24 problems. If I were to give them a worksheet with 24 problems and tell them to sit at their desk and solve them, they would moan and get bored. Scoot allows them movement and the feeling that each spot is something new.

Copy the game cards on colored paper and place them where you want the students rotating. Watch my reflection on Scoot Logistics...I have tried a few methods, but am still working towards the ultimate management tool for Scoot in my classroom.

Make sure the kids have their recording sheet and place them in position to work their first problem, check the resources to see my students ready to play in the hallway. Also, you can see a video of my students solving their problems. My students have learned multiple strategies to solve addition problems, and I am at the beginning of my unit on subtraction so we are just beginning to learn how to use strategies for subtraction, including using objects, drawing pictures, and using number lines. If your students are more advanced and already know strategies well, please make manipulatives available or allow them to draw pictures on the back of their recording sheet. Announce, "It's time to Scoot!" They will continue to rotate until they have finished all problems or you run out of time.

5 minutes

To close out the lesson, I ask 3-5 students share one of the subtraction problems they solved and to demonstrate the strategy they used to find the answer.