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.

• Display the two different circles that were made, or the images in the student book.
• “Hicimos estos dos círculos. ¿Qué observan acerca de ellos?” // “We made these two circles. What do you notice about them?” (One circle has pieces that all look the same. The other circle has a tiny piece and some bigger pieces. Both have 4 pieces but the pieces are different sizes.)

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).

• Invite previously identified students to share.
• “¿Su papel está doblado de una manera en la que cada parte tiene el mismo tamaño? ¿Cómo lo saben?” // “Is your paper folded so that each piece is the same size? How do you know?” (Yes, the pieces line up perfectly. No, when I fold it on the line, one piece is bigger.)

• Consider cutting out the pieces and laying them on top of one another to show whether or not they are the same size.

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.

If students attempt to create fourths by guessing-and-checking about the placement of three vertical lines, consider asking:

• “¿Cuántas partes iguales estás tratando de crear?” // “How many equal pieces are you trying to create?”
• “¿Cómo puedes asegurarte de que todas las partes tienen el mismo tamaño? ¿Cómo doblarías esta figura para obtener 4 partes iguales?” // “How can you make sure that the pieces are the same size? How could you fold this shape to make 4 equal pieces?”

• Invite previously identified students to share.
• “¿Todas estas figuras muestran cuartos? ¿Cómo lo saben?” // “Do all of these shapes show fourths? How do you know?” (Yes, each shape has 4 equal pieces. All pieces are the same size.)
• “Cuando partimos una figura en cuatro partes iguales, la figura queda partida en cuartos. También podemos decir que la figura está partida en cuartas partes” // “When we split a shape into four equal pieces, the shape is split into fourths. We can also say that the shape is split into quarters.”