In this activity, students use a variety of materials to design and create headphones that absorb sound.

This task is for instruction purposes. Part (b) is subtle and the solution presented here uses a "dynamic" view of triangles with two side lengths fixed. This helps pave the way toward what students will see later in trigonometry but some guidance will likely be needed in order to get students started on this path.

Standard 8.NS.1 requires students to "convert a decimal expansion which repeats eventually into a rational number." Despite this choice of wording, the numbers in this task are rational numbers regardless of choice of representation. For example, 0.333 and 1/3 are two different ways of representing the same number.

This task provides an opportunity to work on the Standard for Mathematical Practice 3 Construct Viable Arguments and Critique the Reasoning of Others.

Students learn about using renewable energy from the Sun for heating and cooking as they build and compare the performance of four solar cooker designs. They explore the concepts of insulation, reflection, absorption, conduction and convection.

While the task as written does not explicitly use the term "unit rate," most of the work students will do amounts to finding unit rates. A recipe context works especially well since there are so many different pair-wise ratios to consider.

The author explains heat transfer and how it applies to living in extremely cold environments.

This article highlights the five essential components of cooperative learning, provides a quick overview of the research behind the strategy, describes three of the most common types, and offers ideas on how to get started using cooperative learning at the elementary level.

The concepts that underlie the fourth essential principle of climate literacy ("Climate varies over space and time through both natural and man-made processes.") are too complex for students in early and upper-level elementary school, but the foundational knowledge can be taught within existing curriculums and standards. This foundational knowledge will lead to understanding in later years. The author shows the correlation to the national science education standards, identifies misconceptions among elementary school students, suggests formative assessment probes, and identifies lessons and activities to make curriculum connections. The free, online magazine Beyond Weather and the Water Cycle is based on the seven essential principles of the climate sciences.

Students learn about the many types of expenses associated with building a bridge. Working like engineers, they estimate the cost for materials for a bridge member of varying sizes. After making calculations, they graph their results to compare how costs change depending on the use of different materials (steel vs. concrete). They conclude by creating a proposal for a city bridge design based on their findings.

Students practice counting sequences by standing in a circle and counting one by one.

Students who work on this task will benefit in seeing that given a quantity, there is often more than one way to represent it, which is a precursor to understanding the concept of equivalent expressions.

This challenging problem and brainteaser gives first graders an opportunity to compose and decompose squares.

This is an instructional task related to deepening place-value concepts. The important piece of knowledge upon which students need to draw is that 10 tens is 1 hundred.

This task involves solving equations with rational coefficients, and requires students to use the distributive law ("combine like terms"). The equation also provides opportunities for students to observe structure in the equation to find a quicker solution, as in the second solution presented.

This article introduces a free online collection of images, video clips, and animations that teachers can use in creating resources for use with students. The four steps in creating a video clip, an animation, or other resource are presented.

This article provides an overview of Teaching Tolerance, a project of the Southern Poverty Law Center that provides educators with free resources around the areas of equity, justice, and tolerance.

This article discusses how creating Readers Theater scripts from informational text can improve fluency and build comprehension.

This article discusses the importance of student feedback in creating a respectful, equitable classroom.