When students plot irrational numbers on the number line, it helps reinforce the idea that they fit into a number system that includes the more familiar integer and rational numbers.

This learning video addresses a particular problem of selection bias, a statistical bias in which there is an error in choosing the individuals or groups to make broader inferences. Rather than delve into this broad topic via formal statistics, we investigate how it may appear in our everyday lives, sometimes distorting our perceptions of people, places and events, unless we are careful. When people are picked at random from two groups of different sizes, most of those selected usually come from the bigger group. That means we will hear more about the experience of the bigger group than that of the smaller one. This isn't always a bad thing, but it isn't always a good thing either. Because big groups ''speak louder,'' we have to be careful when we write mathematical formulas about what happened in the two groups. We think about this issue in this video, with examples that involve theaters, buses, and lemons. The prerequisite for this video lesson is a familiarity with algebra. It will take about one hour to complete, and the only materials needed are a blackboard and chalk.

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.

Spreadsheets Across Curriculum module/Introductory chemistry course. Students build spreadsheets to examine unit conversions between the metric and English systems. Spreadsheet level: Beginner.

In this activity, students identify spirals and other shapes present in nature and discuss at what sizes or scales these shapes exist. Examples include a hurricane, foraminifera, nautilus, and a galaxy. They will discuss the differences and similarities of each of these spirals and investigate the powers of ten that identify the scales at which these different examples exist.

This is a third-grade math lesson on the topic of tornadoes and natural disasters. Students will enter data from an internet search on the number of tornadoes occurring in each state into a spreadsheet. Students will analyze and determine which states are the most active in tornado occurrences and create bar graphs and a scaled picture graph from the data collected. This unit was created as part of the ALEX Interdisciplinary Resource Development Summit.

This article is about the isoperimetric theorem. It states the theorem, explains its history and uses examples and exercises to demonstrate it. The resource is from PUMAS - Practical Uses of Math and Science - a collection of brief examples created by scientists and engineers showing how math and science topics taught in K-12 classes have real world applications.

An interactive applet and associated web page that demonstrate isosceles triangles (two sides the same length). The applet presents a triangle where the user can drag any vertex. As the vertex is dragged the others move automatically to keep the triangle isosceles. The angles are also updated continuously to show that the base angles are always congruent. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Are all atoms of an element the same? How can you tell one isotope from another? Use the sim to learn about isotopes and how abundance relates to the average atomic mass of an element.

The purpose of this task is for students to apply their knowledge of integers in a real-world context.

It's Your Paycheck! is designed to introduce personal finance content. Course participants learn about a variety of personal finance topics including the link between education and income, budgeting, the benefits of saving, and credit reports. These learning modules will help participants make sense of W-2s, W-4s, pay -day Loans and APRs in an interactive online format. It's Your Paycheck! consists of nine individual programs that can be used together or individually to enhance personal finance learning.

Students learn about complex networks and how to use graphs to represent them. They also learn that graph theory is a useful part of mathematics for studying complex networks in diverse applications of science and engineering, including neural networks in the brain, biochemical reaction networks in cells, communication networks, such as the internet, and social networks. Students are also introduced to random processes on networks. An illustrative example shows how a random process can be used to represent the spread of an infectious disease, such as the flu, on a social network of students, and demonstrates how scientists and engineers use mathematics and computers to model and simulate random processes on complex networks for the purposes of learning more about our world and creating solutions to improve our health, happiness and safety.

JUNG ??? the Java Universal Network/Graph Framework--is a software library that provides a common and extensive language for the modeling, analysis, and visualization of data that can be represented as a graph or network.

The purpose of this task is to help students articulate their addition strategies and would be most appropriately used once students have a solid understanding of coin values.

Building on their fifth grade experiences with operations on decimal numbers, sixth grade students should find the task to be relatively easy. The emphasis here is on whether students are actually fluent with the computations, so teachers could use this as a formative assessment task if they monitor how students solve the problem.

The purpose of this task is to present students with a situation where it is natural to add fraction with unlike denominators; it can be used for either assessment or instructional purposes.

This task is closely related to very important material about similarity and ratios in geometry.

The purpose of this task is to present students with a context where they need to explain why two simple fractions are equivalent.