This Warm-up prompts students to carefully analyze and compare shapes that are split into pieces. In making comparisons, students have a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminology students use to talk about characteristics of shapes and pieces of shapes. To help all students distinguish the composite shapes from the smaller shapes of which they are made, invite students to clarify or show what they mean when they describe attributes of the shapes they see in each image.

• Display Shape D.
• “If this was a piece of paper, how could you fold it to make these pieces?” (Take the bottom right corner and fold it up to the top left corner.)
• Repeat with Shape A.

The purpose of this activity is for students to recognize the difference between equal and unequal pieces. Students work together to make circles from the pieces they are given. After some circles have been made, students discuss what they notice about each circle. Both circles have four pieces, however one has equal-size pieces and the other doesn't.

The purpose of this activity is for students to fold circles and squares into two or four equal pieces. To make equal pieces, some students may partition the shape by folding it down the middle (and folding again for fourths) and matching up the edges of the shapes. There are several ways students may fold their square into equal pieces—vertically, horizontally, or diagonally—although each way gives different shaped pieces. There are many ways to fold the circle so that the size and the shape of the pieces when it is folded are the same (MP8).

The purpose of this activity is to introduce students to the terms halves and fourths. In the Launch, students explore examples and nonexamples of shapes split into halves and fourths and develop a shared understanding of what these terms mean (MP6). Students then draw lines to partition shapes into halves or fourths. During the Activity Synthesis, students learn that the term “quarters” means the same as “fourths.” Fourths and quarters will be used interchangeably throughout this section.