Module 8 Lesson 7 & 8

Objective Interpret equal shares in composite shapes as halves, thirds, and fourths.

CORE Fluency Practice Sets On your mark, get set, THINK!

Rename for the Smaller Unit 121 = ____ tens _____ ones. 203 I’m going to give you a number in unit form. I want you to rename 1 of the hundreds for 10 tens and then tell me how many hundreds, tens, or ones. Ready? 213 305 315 204 224 108 158 = _____ tens ____ ones. 158 Say the number sentence. 908 968

Application Problem Mrs. Libarian’s students are picking up tangram pieces. They collect 13 parallelograms, 24 large triangles, 24 small triangles, and 13 medium triangles. The rest are squares. If they collect 97 pieces in all, how many squares are there?

Concept Development Let’s continue exploring ways to compose new shapes using our tangram pieces. Start with just the two smallest triangles. What shapes can you make that you can name? What is the name of this polygon? How many parts are in this large triangle? Are the parts equal? We can say this triangle is made up of two equal shares, or parts, called halves. Part 1: Using Tangrams to Create Composite Shapes Described as Halves Materials: (T) Tangram pieces (Lesson 6), document camera, chart paper, pattern blocks (S) Tangram pieces (Lesson 6), pattern blocks in individual plastic bags (set of 1 hexagon, 4 squares, 3 triangles, 2 trapezoids, 3 wide (not thin) rhombuses) Have students take out their tangram pieces. Distribute individual bags of pattern block pieces for later use. Circulate as students move the pieces to make new shapes. Choose three students to place their shapes under the document camera to show a larger triangle, a parallelogram with no square corners, and a parallelogram that is a square, respectively.

Concept Development What is the name of this polygon? How many parts are in this parallelogram? Are the parts equal? How many parts are in this square?

Concept Development Let’s label this chart Halves, or 2 Equal Parts. If you didn’t make one of these shapes, move your pieces to make the shape now. If you did make all the shapes, try moving back and forth between them smoothly. Can we make halves by putting together a small triangle and a parallelogram? Why or why not? Discuss with your partner. That’s right. To be halves, the two parts must be equal in size, which means they take up the same amount of space. How many halves make a whole? Give me a complete sentence. Wait for students to try all three shapes.

Concept Development Let’s explore halves using pattern blocks. Start with a hexagon. What smaller polygon could you use to cover half of the hexagon? Yes. One trapezoid covers half the hexagon. Put another trapezoid on top to cover the whole hexagon. How many trapezoids make a whole hexagon? Are they equal shares? How many halves are in the hexagon? Let’s record this on our Halves chart. Part 2: Using Pattern Blocks to Create Composite Shapes Described as Halves, Thirds, and Fourths Place a hexagon under the document camera as students get a hexagon from among their shapes. Allow students time to experiment and find the trapezoid. Place two trapezoids on top of the hexagon under the document camera as students do the same. Repeat this process for a rhombus, covering it with two equilateral triangles, and record on the chart.

Concept Development Let’s try something different. This time we’ll use a trapezoid. Can you cover the trapezoid with three smaller polygons? What shape did you use? Are the shapes equal in size? How many equal shares compose a whole trapezoid? We call three equal shares, or parts, thirds. Let’s make a new chart and record this. Work with a partner. Leave one triangle on, and cover the rest of the trapezoid with a rhombus. Talk with your partner: Are these halves? Why or why not? Place a trapezoid under the document camera, as students get a trapezoid from among their shapes. Allow students time to experiment. Model under the document camera as students do the same. Repeat the process for a hexagon covered by three rhombuses, and record on the chart. ***Now, can you make one large square that is created with equal parts? Invite a student to show his or her composite square under the document camera. Have students note how many parts are used to make the square, and if they are even. Introduce them to the term fourths, create a new chart labeled Fourths, or 4 Equal Shares, and draw the shape, partitioned to show the pieces used.

Concept Development Problem 1: Use one pattern block to cover half the rhombus. Complete Problem 1. Share your thinking with your partner. Close your eyes and visualize how you moved the smaller polygons to create the rhombus. Describe how you flip, slide, or turn the pieces. Ask questions such as the following to support deeper analysis of halves: How can looking at angles and sides help you find the block that is half a rhombus? If the rhombus was made from a piece of paper, how many different ways could you cut it to get two halves? Draw the different ways you could cut the rhombus into two halves. Materials: (T) Pattern blocks, Problem Set, document camera (S) Problem Set, pattern blocks in individual plastic bags per pair (set of 1 hexagon, 6 squares, 6 triangles, 2 trapezoids, 3 wide (not thin) rhombuses) Note: The Problem Set is completed throughout the Concept Development. Students work in pairs to encourage math conversations as they explore equal shares using pattern blocks. Students identify and use one pattern block to cover a half, a third, or a fourth of a given shape. They then draw a picture of the composite shape formed by the halves, thirds, and fourths.

Concept Development Problem 2: Use one pattern block to cover half the hexagon. Ask questions such as the following to encourage interpreting different representations of a half: Cover the bottom half of the hexagon with three triangles. Is it still half covered? Why or why not? Cover the bottom half of the hexagon with a rhombus and a triangle. Is it still half covered? Problem 3: Use one pattern block to cover one- third of the hexagon. Ask questions such as the following to encourage deeper understanding of thirds: How many thirds do you need to fill the whole hexagon? Cover one-third with two triangles. Is the hexagon one-third covered? What fraction is not covered?

Concept Development Problem 4: Use one pattern block to cover one-third of the trapezoid. Remember to interpret thirds in relationship to a whole: Use your drawing of the trapezoid formed by thirds to talk about how many small triangles would make a whole hexagon. How many thirds are in the trapezoid? In the hexagon?

Concept Development Problem 5: Use four pattern blocks to make one larger square. Remember to support different understandings of fourths: How many equal shares does the large square have? How many fourths make up the large square? How many fourths equal one whole square? Use your blocks to show that 2 fourths is the same as a half of the large square. Problem 6: Use one pattern block to cover one- sixth of the hexagon. Ask questions such as the following to support thinking about sixths: How many equal parts does the hexagon have? How many sixths make up the hexagon?