This problem helps students practice adding three numbers whose sum are 20 or less.

Overview of cycles of regulation, de-regulation and government in 20th century US capitalism. Created by Sal Khan.

This short video and interactive assessment activity is designed to give fourth graders an overview of 24-hour clocks.

This short video and interactive assessment activity is designed to give fifth graders an overview of 24-hour clocks.

In 1790, Samuel Slater built the first factory in America, based on the secrets of textile manufacturing he brought from England. He built a cotton-spinning mill in Pawtucket, Rhode Island, soon run by water-power. Over the next decade textiles was the dominant industry in the country, with hundreds of companies created.

The 26th Amendment to the United States Constitution bars the federal government, as well as all state and local governments, from using age as a justification for denying the right to vote to any citizen of the United States who is at least 18 years of age. In addition, the Amendment grants Congress the power to “enforce” that prohibition through “appropriate legislation.”

An interactive map that shows electoral college results for presidential elections. Also includes historical elections back to 1789, and various elections for Senate, House of Representatives, and governors. Students can also interactive with and manipulate the map to see how elections would have turned out with different results.

This resource from the National Constitution Center includes an introduction, big questions, recorded class sessions, briefing documents, slide decks, and worksheets about the 27 amendments of the United States Constitutuion.

This description of this activity is a 2-day lesson: Day 1, Field Lab, Day 2, and Classroom Investigation.
In this field lab, children working in groups will collect 3 samples of soil from different locations. Each sample will be placed in a different Ziploc bag, the groups will label the bags and record in their notebooks the location of each sample, including 5 observations about the area near the location the sample was taken from. They will need to make a plan on how to record and label the bags and locations so when we return to the classroom they will have a system for knowing the location. Individually, each student will also include in his/her notebook a question about each area or the soil collected. Groups will discuss own observation/questions. Each group will share 2 observations they made and 1 question they are wondering. The groups will bring their soil samples back to the classroom. Once back in the classroom, the students will work to create a data recording system and develop an investigable question about the soil. The students will also have available other sample soils provided by the teacher. Students will use the materials and observe the soils and record their findings. The groups would share their data and create a class chart of the information. Ask: What can we notice from this information? What questions do you have about the information?

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important aspects of the task and its potential use.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important aspects of the task and its potential use.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: * Color the inside of all the triangles blue. * Color the inside of all the quadrilaterals red. * Color the inside of all the pentagons orange. * Color...

Next lets build a diagram that break rotation into smaller parts. The next exercise will give us a chance to build our understanding of this diagram.

Let's look more closely at how light behaves when it strikes an object. We'll cover diffuse and specular surface responses.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Materials * Alexander, Who Used to be Rich Last Sunday by Judith Viorst * Plastic coins * Labels for items Alexander spent his money on (attached) * Pa...

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: One day, Frog and Toad were sitting together on a lily pad. Some lily pads were in a line across the pond. In the morning, Frog hopped three lily pads ...

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Materials * How Big is a Foot? by Rolf Myller * Masking tape * Enough 12-inch (one foot) rulers for every student or pair of students * One yardstick *...