Show What You Know-Solving Subtraction Problems (K/1st Grade)

Title: Show What You Know! Solving Subtraction Problems

Essential Questions: How can we solve subtraction problems by using strategies we know?

Objectives: Today you will learn about what it means to subtract and a strategy for solving subtraction using a ten frame.
-Students will review and discuss subtraction terms and strategies.
-Students will practice using ten frames as a strategy to solve subtraction problems.
-Students will be able to use at least one subtraction strategy to help them solve subtraction problems.

Vocabulary: Take away, give away, pay, fewer, less, difference, how many more…

Materials/Resources: Ten frames, Subtraction Song Chart, strategy chart, counters, paper, pencils, markers, I-pad (Subtraction, avatar video and ten frame fill), computer (learnzillion.com) are the resources that will be used.

Description/Rationale: The purpose of this lesson is to help students understand the concept behind the abstract symbols used in subtraction. Specifically, Kindergarteners are still learning number symbols and alphabets as well as the plus sign so distinguishing symbols and what they represent when presented with them are extremely important. All students need concept development to retain such skills. This lesson will teach students a new strategy for solving subtraction as well as provide a pictorial representation of subtraction. Language development of vocabulary like minus, take away, less and fewer is also important for all students in math progression as these terms will be used in word problems and comparing amounts throughout school and in the real world. First graders will have a combination of addition and subtraction. Students will discuss these concepts, learn and practice a new strategy and then use the strategy that works best for them in their independent and partner tasks. Upon completion of tasks some students will interview each other to discuss which strategy they used and why and how they used it. Others will create an avatar cartoon video or a song to share their strategy for solving subtraction problems.

Mini-lesson/Think Aloud: Over the past few weeks we have been learning about numbers and how they can be put together or taken apart. Recently, we have been showing how we take numbers apart or subtract. We learned a few strategies to solve subtraction problems like using counters to take away, drawing pictures to model subtraction and counting back on a number line. Today we will learn more about what it means to subtract. We will review the terms that let us know when to subtract and learn a new strategy using a ten frame to like we did with adding.

Warm-up Partner/Activity: (5 min)- Can you Show It with one Ten Frame?” game. You will work with a partner. Each partnership will have one ten frame. Think of a number that you cannot make or represent on one ten frame with counters. Write the number down and discuss why it cannot be shown on one ten frame. Share you numbers and explanation with the class. (Some students may require guided support)
(5 min) Partner Interview: What strategy did you use?
Can you show me how you solved the problem? What else did you have to do?
Whole Group/small group Activity:(5 min)- Play add or Subtract Game (tactile/Kinesthetic). Explain your thinking.

(3 min)- Subtraction Song & Movement Break (Auditory/Kinesthetic)-Students will stand up, move their feet, clap their hands and snap their fingers as they sing the class subtraction song with a blues-like feel that takes them through social stories or situations in which we need to subtract such as sharing candy, spending money, and eating all of the cookies at snack time.
(2 min) Review and discuss subtraction terms (modeling/reinforcing)-Review and discuss subtraction terms that are included in the song such as take away, give away, less, fewer, pay, nothing more and zero

(5-10 min)- Practice with ten frame-

(10 min)- Differentiated Subtraction Tasks-Kindergarten students will have three different tasks one with a word problem and number sentence, one with only number sentences within 5 and the other with number sentences within 10 and each with a space to explain the strategy they used through writing, drawing, or dictation. 1st graders will be given mixed addition and subtraction problems with subtraction word problems within 10 and the other task will be problems within 20. They will have a space provided to explain the strategy they used to solve the problem.


Independent Activity/ Assessment:(5-10 min)-Differentiated Exit Slips assess understanding of five and ten frame strategy, solving a subtraction sentence using a strategy of your own and writing about or representing a given image that shows subtraction including a number sentence. Some students will write about the strategy they learned about and the strategy they used, while others will create a song to share or avatar cartoon video about the strategy that worked best for them.

CCLS. Mathematical Practice Standards 1&2

Differentiation/UDL/DOK:
-All learners will be engaged in games that involve critical thinking an reasoning that include a tactile/kinesthetic component to support attention and retention of information.
-Modeling with manipulative and pictures will support understanding and retention for ELL, non-readers, and SWD and all learners to be able to utilize strategy for the purpose of the lesson.
-The tasks and Exit slip will include open questions that allow for more than one way to respond and demonstrate understanding. This will create multiple entry points for students to participate and not limit them to one solution to a problem. Discussions will further expand student’s knowledge by reinforcing the idea that there are other ways to solve subtraction problems, than the way that they selected to use.
Differentiated exit slips provide modified assessment of mastery based on ability and readiness.

Standards:Connections to CCLS Language and Speaking and Listening standards
CCLS.MATH.CONTENT.K.OA.A.1:
Represent addition and subtraction with objects, fingers, mental images, drawings, sounds(e.g., claps), acting out situations, verbal explanations, expressions, or equations.
CCLS.MATH.CONTENT.K.OA.A.2:
Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.

CCLS.MATH.CONTENT.1.OA.A.1:
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.
C.C. K-12 Mathematical Practice standard 1: Make sense of problems and persevere in solving them.
C.C. K-12 Mathematical Practice standard 2: Reason abstractly and quantitatively.
Follow-up/H.W Kindergarten- Comparing amounts. First Grade- Solving 2-digit Subtraction problems using base ten blocks
Closing/Share:(5 min)- Show and Share your work (video, cartoon, song, or oral presentation. Now let’s discuss what we have learned today before we wrap up.

Focus Questions:

Can we use one five frame to represent and solve 10-3?

Can we use one ten frame to represent and solve 13-5?
Why or Why not?

What does it mean to subtract?

When you subtract do you end up with more or less?

Which symbol lets us know we need to subtract?

Which words let us know to subtract?

Can you compare and contrast addition and subtraction?

How are addition and subtraction alike or different from each other?

What Strategy did you use to solve the problems?

Can you show us how you solved the problem? Explain your thinking.

What did you learn?

Why are you learning this?