Aerogel, commonly called "frozen smoke," is a super-material with some amazing properties. In this lesson and its associated activity, students learn about this silicon-based solid with a sponge-like structure. Students also learn about density and how aerogel is 99.8% air by volume, making it the lightest solid known to humans! Further, students learn about basic heat transfer and how aerogel is a great thermal insulator, having 39 times more insulation than the best fiberglass insulation. Students also learn about the wide array of aerogel applications.

In this task, the students are not asked to find an answer, but are asked to analyze word problems and explain their thinking. In the process, they are faced with varying ways of thinking about multiplication.

This task provides a construction of the angle bisector of an angle by reducing it to the bisection of an angle to finding the midpoint of a line segment. It is worth observing the symmetry -- for both finding midpoints and bisecting angles, the goal is to cut an object into two equal parts. The conclusion of this task is that they are, in a sense, of exactly equivalent difficulty -- bisecting a segment allows us to bisect and angle (part a) and, conversely, bisecting an angle allows us to bisect a segment (part b). In addition to seeing how these two constructions are related, the task also provides an opportunity for students to use two different triangle congruence criteria: SSS and SAS.

Students analyze the relationship between wheel radius, linear velocity and angular velocity by using LEGO(TM) MINDSTORMS(TM) NXT robots. Given various robots with different wheel sizes and fixed motor speeds, they predict which has the fastest linear velocity. Then student teams collect and graph data to analyze the relationships between wheel size and linear velocity and find the angular velocity of the robot given its motor speed. Students explore other ways to increase linear velocity by changing motor speeds, and discuss and evaluate the optimal wheel size and desired linear velocities on vehicles.

In this task students have to interpret expressions involving two variables in the context of a real world situation. All given expressions can be interpreted as quantities that one might study when looking at two animal populations.

education, schools,

In this problem students are comparing a very small quantity with a very large quantity using the metric system. The metric system is especially convenient when comparing measurements using scientific notations since different units within the system are related by powers of ten.

This task requires students to work with very large and small values expressed both in scientific notation and in decimal notation (standard form). In addition, students need to convert units of mass.

This textbook provides a toolbox, a guidebook, and an instruction manual for researchers and interventionists who want to conceptualize and study applied problems from a developmental systems perspective, and for those who want to teach their graduate (or advanced undergraduate) students how to do this. It is designed to be useful to practitioners who focus on applied developmental problems, such as improving the important developmental contexts where people live, learn, and work, including the applied professions in education, social work, counseling, health care, community development, and business, all of which at their core are concerned with optimizing the development of their students, clients, patients, workers, citizens, and others whose lives they touch.

In this activity, students construct their own rocket-powered boat called an "aqua-thruster." These aqua-thrusters will be made from a film canister and will use carbon dioxide gas produced from a chemical reaction between an antacid tablet and water to propel it. Students observe the effect that surface area of this simulated solid rocket fuel has on thrust.

In this math activity, learners explore the history of the Stomachion (an ancient tangram-type puzzle), use the pieces to create other figures, learn about symmetry and transformations, and investigate the areas of the pieces. The Stomachion, believed to have been created by Archimedes, consists of 14 pieces cut from a square, which can be rearranged to form other interesting shapes.

The famous story of Archimedes running through the streets of Syracuse (in Sicily during the third century bc) shouting ''Eureka!!!'' (I have found it) reportedly occurred after he solved this problem. The problem combines the ideas of ratio and proportion within the context of density of matter.

Students explore the interface between architecture and engineering. In the associated hands-on activity, students act as both architects and engineers by designing and building a small parking garage.

In this problem, students are given a picture of two triangles that appear to be similar, but whose similarity cannot be proven without further information. Asking students to provide a sequence of similarity transformations that maps one triangle to the other focuses them on the work of standard G-SRT.2, using the definition of similarity in terms of similarity transformations.

The year is 2032 and your class has successfully achieved a manned mission to Mars! After several explorations of the Red Planet, one question is still being debated: "Is there life on Mars?" The class is challenged with the task of establishing criteria to help look for signs of life. Student explorers conduct a scientific experiment in which they evaluate three "Martian" soil samples and determine if any contain life.

This problem is part of a very rich tradition of problems looking to maximize the area enclosed by a shape with fixed perimeter. Only three shapes are considered here because the problem is difficult for more irregular shapes.

The purpose of this task is primarily assessment-oriented, asking students to demonstrate knowledge of how to determine the congruency of triangles.

This this task about mixing paint requires students to graph ratios on a coordinate plane. It is a standard language in ratio problem.