Subtraction Hide and Seek

 
 CONTENT  AREAS: 

Whole number subtraction 

 

GRADE  LEVEL:  

            1st and 2nd

 

MATERIALS   NEEDED: 

            Making Hide and Seek card:

                        Large index cards

                        Markers

                        Stickers or other cut out pictures

            When doing lesson:

                        Hide and Seek cards

                        Pencil

                        Paper

 

KEY   CONCEPTS: 

Subtraction   

EALR'S (Make the connections clear and specific):

       1.1 Use pictures or objects to demonstrate an understanding of whole numbers.

é        Each index card will have an illustration of the numbers for the students to look at and use as aids in solving the problem.  They can also use beans or other counting tools if they need more visualization.

1.1 Show an understanding of whole number subtraction

é        Using the visual images and information on the Hide and Seek cards to determine what the subtraction problem is and how it can be worked out.

1.1 Use mental arithmetic to do subtraction

é        Once students determine the subtraction problem they are to try their best to solve the problem.

1.1 Use pen and pencil work to do subtraction

é        Once students determine what the problem is they need to be able to write the problem out and solve it.

           

GOALS:

Students will be able to write and solve subtraction problems.

 

OBJECTIVES: 

After practicing as a whole class or in small groups with the Hide and Seek cards, students will be able to identify subtraction problems and know how to write them as a subtraction problem.   Once students are able to identify and write out the subtractions, they should be able to solve the problems using the images on the cards or other objects.


 PROCEDURES: 

Phase 1: Provide Objectives and Establish Set/ Introduction & Pre-assessment:

      Using Hide and Seek cards should be used once students have some understanding of subtraction or as a form of review. They will help to reinforce current knowledge and increase the ability to turn word sentences into number sentences.  In order to that I would introduce the activity by asking students questions such as:

1.       Who can tell me what we studied in math yesterday?

2.      What does it mean to subtract?

3.      Can you think of any times in real life that you would need to subtract?

4.      If you had to turn those real life experiences into a math problem how do you think you would write it?

Questions such as these should help to activate prior knowledge so that the teacher can expand and begin teaching the lesson.

 

Activity:

Phase 2: Demonstrate knowledge or skill

1.       Explain that today the class is going to practice our subtraction and work on turning word statements into math problems/number sentences. 

2.      Explain that a word statement is verbally saying the numbers and math problem i.e. four plus six equals ten. Writing a number sentence is when you use numbers to represent a math problem, i.e. 4+6=10.

3.      Show the class a Hide and Seek card with both numbers hidden so that all the pictures are showing.  Explain how the cards work as well as how to turn the information on the card into a number sentence.  (For more detail refer to the steps in guided practice and simplify)

 

Phase 3: Guided Practice

1.       Ask the class how many things they see. Once they answer, uncover the left number flap that will reveal the whole number value.

2.      Cover the top pictures with a flap, and then ask the class if they can tell how many are hiding.  Once students start giving answers be sure to ask how they came to that conclusion.  Encourage students to use manipulatives to do the problem or use other strategies such as; using their fingers or counting up from the number shown. (Counting up would have been a previous lesson plan).

3.      Once the students have worked through the problem flip over the hidden number and explain why that was the hidden amount.

4.      Summarize or ask someone to summarize the whole process and the conclusions.  Once that is done start asking the students how they might write this as a math problem.  If students don’t come up with the correct method you can begin asking questions to encourage them to the answer.

5.      Explain that the operation is the whole number minus the hidden number.

 

Phase 4: Check for Understanding and Provide Feedback

1.       Repeat this process as a class at least 5 times depending on how well the class understands.  Many students will be in a delequalibrium during the guided practice.  It is important that students are at least beginning to understand before you let them practice on their own.

2.      Explain that you will be pairing the students up to practice with their own cards. As they do the problems they need to be writing down their math problems/number sentences. Each card will have a number on the back, representing the card number for grading purposes. Tell students to write the card number next to the problem. 

3.      Allow the class an opportunity to ask for clarification before splitting them into pairs.

 

Phase 5: Provide Extended Practice and Transfer

1.       Split the class, pass out the cards and allow the students to work with their partners.  During this time walk around the class and observe what the students are doing using the checklist.  When students appear to be having difficulty stop and help them through.  The whole time students are practicing they should be elaborating on their understanding.

 

Closure:

      Gather the class’s attention to do a whole class review and wrap-up.  Hopefully students will have crystallized understanding by now, but don’t expect everyone to.   Ask if anyone feels comfortable coming up as pairs and demonstrating what they did with a card.  Make sure students explain why they are doing things as they do them.  After a few people have demonstrated, explain to the class why it is important that they learn to change word sentences into number sentences.   After the class understands this concept collect the cards and their work.

 

POST-ASSESSMENT/Testing:

            As students work in their small groups they should be writing down each math problem and the solution.  Once they are finished practicing they can hand in their work so that you can determine their understanding of writing math problems as well as working through subtraction.  When doing this it is important that the cards are numbered and that the cards numbers are turned in with the problems so that you can determine which card is presented in their work. It is also important to walk around while the class is working on the cards to determine what strategies students are using to solve the problems of the card.  In order to do this I suggest observing students as well as asking them to explain their reasoning.  This checklist is one suggestion for ways to keep track of the different skills and techniques the students are using.

 

 

Instructions for making Hide and Seek cards:

1. Fold card in half hot dog style

 
2. Divide the card into thirds horizontally. You can do this mentally or physically by drawing lines W/PENCIL or folding the paper.  Cut the outer thirds along the centerfold line.  Do not cut into the center third.
3. Decide what you want the subtraction problem to be.  The largest number should be below 20.
4. On the lower left hand corner write the whole number large enough for the class to read.
5. On the upper right hand corner write the number you want to be subtracted from the whole number. That will be the number in hiding.

 
6. In the top center square put the same # of drawings, stamps or stickers as presented by your number in the upper right corner.
7. In the bottom center square put the same # of drawings, stickers or stamps required for you to have the whole number presented when both center squares are showing.