Lesson 9 Equal Pieces

    • Let’s split shapes into equal-size pieces.

Warm-up Which One Doesn’t Belong: Pieces of Shapes

Which one doesn’t belong?

  1. Square, partitioned into 4 equal parts, 4 parts shaded.
  2. Shape, 6 sides, made of 4 triangles of the same size.
  3. Shape, made of 4 triangles of different sizes.
  4. Square, partitioned into 2 shaded triangles with equal length sides.

Activity 1 Build a Circle

Problem 1

Today we are going to make circles. Each circle will be made up of four pieces. You will walk around and find three other people who have pieces that fit with yours to make a circle.

Problem 2

Synthesis:

Partitioned circle.

Which of these shows equal pieces that make a circle?

Activity 2 Fold into Equal Pieces

  1. Cut out one circle and one square.

    Fold each shape so that there are 2 equal pieces.

    Be ready to explain how you know your shape has 2 equal pieces.

  2. Cut out one circle and one square.

    Fold each shape so that there are 4 equal pieces.

    Be ready to explain how you know your shape has 4 equal pieces.

Activity 3 Halves or Fourths

Chart, 2 groups. Split into halves, shapes with 2 equal parts. Not split into halves, shapes not partitioned into 2 equal parts.
Chart, 2 groups. Split into fourths, shapes with 4 equal parts. Not split into fourths, shapes not partitioned into 4 equal parts.

  1. Split each shape into halves.

    2 squares, different sizes.

  2. Split each shape into fourths.

    2 rectangles, different sizes.

  3. Split each shape into fourths.

    2 circles, different sizes.

  4. Split each shape into halves.

    2 rectangles, different sizes.

  5. Split each shape into halves.

    2 circles, different sizes.

  6. Split each shape into fourths.

    2 squares, different sizes.

Practice Problem

Problem 1

  1. Han drew this picture to show a circle split into fourths.

    Circle, partitioned into 4 parts. One half. Three other parts the same size.

    Do you agree with Han?

    Show your thinking using drawings, numbers, or words.

  2. Split the rectangle into fourths.

    Rectangle.