In this hands-on botany activity, learners sprout vegetables in film canisters. Learners grow nine seeds each of cabbage, radish, and parsley, experimenting with changing one variable (light, water, or temperature) to explore differences in the germination preferences of the plants. If film canisters aren't available, other small, opaque containers with lids can be substituted.

Filtering is the process of removing or separating the unwanted part of a mixture. In signal processing, filtering is specifically used to remove or extract part of a signal, and this can be accomplished using an analog circuit or a digital device (such as a computer). In this lesson, students learn the impact filtering can have on different types of signals, the concepts of frequency and spectrum, and the connections these topics have to real-world signals such as musical signals. Students also learn the roles that these concepts play in designing different types of filters. The lesson content prepares students for the associated activity in which they use an online demo and a variety of filters to identify the message in a distress signal heavily corrupted by noise.

Students learn the basic principles of filtering as well as how to apply digital filters to extract part of an audio signal by using an interactive online demo website. They apply this knowledge in order to isolate a voice recording from a heavily noise-contaminated sound wave. After completing the associated lesson, expect students to be able to attempt (and many successfully finish) this activity with minimal help from the instructor.

This online lifetime value calculator quickly demonstrates the financial value of a satisfied customer.

This simple-looking problem reveals much about how well students understand unit fractions as well as representing fractions on a number line.

In this activity students will learn the basic concept of Global Positioning Systems (GPS) using triangulation and measurement on a small scale in the classroom. Students discover how GPS and navigation integrate mathematic and scientific concepts to create a standard for locating people and objects. This activity helps students understand both the need for and methods of navigation.

Students create their own simple compasses using thread, needle and water in a bowl and learn how it works.

The purpose of this task is to have students work on a sequence of area problems that shows the advantage of increasingly abstract strategies in preparation for developing general area formulas for parallelograms and triangles.

This task asks students to find and use two different common denominators to add the given fractions. The purpose of this question is to help students realize that they can use any common denominator to find a solution, not just the least common denominator.

This task asks students to use two different denominators to subtract fractions. The purpose of this is to help students realize that any common denominator will work, not just the least common denominator.

In this task students have the opportunity to construct linear and exponential functions, including arithmetic and geometric sequences, given a graph, a description of a relationship, or two input-output pairs (include reading these from a table).

This real world problem is appropriate for mental mathematics and students should be encouraged to think through the solution mentally.

The purpose of this task is to give 4th grade students a problem involving an unknown quantity that has a clear visual representation. Students must understand that the four interior angles of a rectangle are all right angles and that right angles have a measure of 90_ and that angle measure is additive.

This tasks examines how to calculate the area of an equilateral triangle using high school geometry.

This task helps students solidify their understanding of linear functions and push them to be more fluent in their reasoning about slope and y-intercepts. This task has also produced a reasonable starting place for discussing point-slope form of a linear equation.

This task "Uses facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure (7.G.5)" except that it requires students to know, in addition, something about parallel lines, which students will not see until 8th grade.