This lesson explains how average velocity can be represented by a positive or negative sign. It is 1 of 2 in the series titled "Average Velocity & Sign Notation." [6:44]

This website from the BBC is a great introduction to averages (mean, median, and mode) and will take you through some interactive learning activities. A practice test and worksheet are also provided.

Activities and factsheets exploring ratios and proportions in everyday life. Interactive, colorful, and fun.

Use fractions and percentages to solve probability problems. Skillwise provides five factsheets, four quizzes, four worksheets, and a game pertaining to probability.

Kindergarteners need a basic understanding of measurement that leads them to know that the smaller the unit the more it takes to measure the same object using less larger units.

This task provides a real world context for interpreting and solving exponential equations. There are two solutions provided for part (a). The first solution demonstrates how to deduce the conclusion by thinking in terms of the functions and their rates of change. The second approach illustrates a rigorous algebraic demonstration that the two populations can never be equal.

In this experiment, two chemicals that can be found around the house will be mixed within a plastic baggie, and several chemical changes will be observed.

This series of word problems requires students to apply the concepts of factors and common factors in a context.

Students groups use balsa wood and glue to build their own towers using some of the techniques they learned from the associated lesson. While general guidelines are provided, give students freedom with their designs and encourage them to implement what they have learned about structural engineering. The winning team design is the tower with the highest strength-to-weight ratio.

The purpose of this task is to provide students with a multi-step problem involving volume and to give them a chance to discuss the difference between exact calculations and their meaning in a context.

This task asks students to use similarity to solve a problem in a context that will be familiar to many, though most students are accustomed to using intuition rather than geometric reasoning to set up the shot.

This video lesson introduces and defines bar graphs, discussing their uses and construction. Includes several multiple-choice questions to check your understanding. [3:13]

Explore a brief history of mathematics in Mesopotamia through the Babylonian Base 60 number system. This video focuses on how a base 60 system does not use fractions or repeating decimals, some of the advantages of a base 60 system, and some components that carried over into the base 10 system we use today, taking math out of the classroom and into the real world.

The purpose of this task is to help students understand what is meant by a base and its corresponding height in a triangle and to be able to correctly identify all three base-height pairs.

This task could be put to good use in an instructional sequence designed to develop knowledge related to students' understanding of linear functions in contexts. Though students could work independently on the task, collaboration with peers is more likely to result in the exploration of a range of interpretations.

This task involves a fairly straightforward decaying exponential. Filling out the table and developing the general formula is complicated only by the need to work with a fraction that requires decisions about rounding and precision.

This task describes two linear functions using two different representations. To draw conclusions about the quantities, students have to find a common way of describing them. We have presented three solutions (1) Finding equations for both functions. (2) Using tables of values. (3) Using graphs.

Students explore the properties of composites using inexpensive materials and processing techniques. They create beams using Laffy Taffy and water, and a choice of various reinforcements (pasta, rice, candies) and fabricating temperatures. Student groups compete for the highest strength beam. They measure flexure strength with three-point bend tests and calculations. Results are compared and discussed to learn how different materials and reinforcement shapes affect material properties and performance.

Using gumdrops and toothpicks, students conduct a large-group, interactive ozone depletion model. Students explore the dynamic and competing upper atmospheric roles of the protective ozone layer, the sun's UV radiation and harmful human-made CFCs (chlorofluorocarbons).