Throughout the course, students have engaged in Warm-up routines, such as How Many Do You See? Exploration Estimation, Which Three Go Together? True or False? and Number Talk. This section enables them to apply the mathematics they have learned (the four operations, fractions, and measurement, in particular) to design warm-ups that incorporate some of these routines.

Each lesson is devoted to a particular routine. Students begin by completing partially created tasks. They practice anticipating responses that others might give to the prompts they pose.

What do you notice? What do you wonder?

Along the way, students gain the skills and insights needed to create an activity from scratch or with minimal scaffolding. In each lesson, students have the option to facilitate their activity with another group in the class.

In this section, students further investigate ideas on measurement (area and perimeter) and data (scaled graphs).

Students begin by analyzing features of tiny houses. They use their knowledge of shapes, perimeter, and area to design their own tiny house, and then write questions about the areas and the perimeters of the shapes in their design.

Later, students apply their knowledge of addition and subtraction to calculate the cost of finishing a room in their tiny house.

In the second half of the section, students focus on data collection and representation. They think about survey questions to ask others in the class and in the school, how to present the answer choices, and how to collect and record a large set of data.

Students then conduct their survey in the school community, organize their data, and represent the data with a scaled graph. They also ask and answer questions about the data.

Write questions that could be answered with your bar graph by completing these sentences.

How many more students liked _________ than _________ ?

How many fewer students liked _________ than _________ ?

In this section, students continue their work of building fluency with multiplication and division. They begin by reflecting on the products within 100 that they know from memory or can find quickly and the products they don’t know yet. Students then practice multiplication facts through games (focusing on those facts that are least familiar to them).

Next students reinforce their understanding of the connections between multiplication and division by matching equations and diagrams that represent the same quantities and relationships. For instance, the equations and , and a diagram of a rectangle, with an area of 56 and a side length of 7, all can describe the same situation.

Here is another example that shows different representations of multiplication and division: 

Which 3 go together?

Students then play games to improve their facility with multiplication and division. They revisit familiar center activities and learn new ones. Compare, Rectangle Rumble, and How Close? are the centers used in this section.

In this section, students revisit and build on important fraction ideas that they have learned in the course. They think about different ways to represent a fraction and to estimate the size of a fraction presented in different forms: as an area diagram, a shaded strip, and a number line.

What fraction of the square is shaded?

What number is represented by the point on the number line?

Students also practice identifying and locating fractions on the number line, using tape to create a number line that shows a large number of fractions.

Later in the section, students consolidate their understanding by analyzing general statements about fractions (for instance, “a fraction is a number less than 1,” or “whole numbers are fractions”). They express their agreement or disagreement with the statements and have the chance to revise their thinking upon discussions with others.