Halves

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Objective

SWBAT divide a whole into halves.

Big Idea

I want my students to develop a strong foundation in fractions and it will begin here with recognizing half of an object.

Rev Them Up

5 minutes

Need: My Half Day by Doris Fisher and Dani Sneed

I will read My Half Day to my class. This is a great book to get my little ones thinking about dividing things into halves and other equal amounts. Today's lesson will focus on creating halves. I want my students to identify how a whole can be divided equally into two pieces. (1.G.A.3). Students need to develop a strong foundation in dividing items into equal shares. This knowledge will be extended into later grades and it is important for them to identify that a whole is made of two halves or four fourths. 

Whole Group Interaction

20 minutes

Need: 2-10" tortillas per student

When I am finished with the book I will give each student 2-10" tortillas and lay them on a paper towel on their desk. Then state;

  • Students how many tortillas are on your desk? (2)
  • Is there anything missing from them or are they whole tortillas? (They are all there, they are whole tortillas.)

Then I will model and show my students to take one tortilla and fold it exactly in half and ask;

  • Students we have folded one tortilla in half and slowly separated it along that line. How many pieces are there now? (2) 
  • Are they the same or different? (They are the same, they are equal) 
  • Now let's lay the whole tortilla next to the tortilla that has two pieces. The two pieces are called one-half because they are one-half of a whole tortilla. We write that with symbols like this 1/2. If I have 1/2 of a tortilla and one whole tortilla, which is more? (The whole tortilla is larger.) So I could say 1>1/2.
  • Do you still have two whole tortillas on your desk? (Yes, we could put the 1/2 plus 1/2 and they would be a whole again.) Go ahead and lay the two halves on top of your whole tortilla, are they they still equal to a whole? (Yes, putting 1/2 with 1/2 we have a whole)

Students will be constructing arguments and critiquing others reasoning during this activity. (MP3). They will have to clearly express their ideas to explain how the shapes are related to each other, equal each other, and are different than one another.

 





Independent Practice

5 minutes

Need: Print and copy Fraction worksheet from the resource section for each student

I will have my students practice dividing items into one-half pieces using the provided worksheet. 

Lesson Closure

10 minutes

Need: 2 Hershey bars; 

  • Let's review what we have learned today. Look at these chocolate bars and tell me what you see. (I see a whole bar, I see a whole with 8 pieces, I see 8 pieces that can be broken into halves.)
  • I am going to break the chocolate bars in half different directions.  What do you see now? ( I see 1/2 here and 1/2 there, I see 2 pieces that equal a whole, I see 2 halves. I see 4 squares and 4 squares.)
  • If I want to share with a friend will I have enough? (yes, I you have equal pieces and can give 1/2 to a friend and keep 1/2 for yourself.)

Make sure and watch the video to see how I break apart the chocolate bars and students discover that breaking it differently still gives them equal parts.