The purpose of this learning video is to show students how to think more freely about math and science problems. Sometimes getting an approximate answer in a much shorter period of time is well worth the time saved. This video explores techniques for making quick, back-of-the-envelope approximations that are not only surprisingly accurate, but are also illuminating for building intuition in understanding science. This video touches upon 10th-grade level Algebra I and first-year high school physics, but the concepts covered (velocity, distance, mass, etc) are basic enough that science-oriented younger students would understand. If desired, teachers may bring in pendula of various lengths, weights to hang, and a stopwatch to measure period. Examples of in- class exercises for between the video segments include: asking students to estimate 29 x 31 without a calculator or paper and pencil; and asking students how close they can get to a black hole without getting sucked in.

This article reprints and links to informational text about the adaptations that allow mammals and fish to survive in polar oceans. Versions are available for students in grades K-1, 2-3 and 4-5. Related science and literacy activities are included.

In this interactive activity from ChemThink, take a closer look at atomic structure, properties, and behaviors.

Explore the interactions between various combinations of two atoms. Turn on the force arrows to see either the total force acting on the atoms or the individual attractive and repulsive forces. Try the "Adjustable Attraction" atom to see how changing the parameters affects the interaction.

This video segment adapted from A Science Odyssey takes a look at the scale of the atom and the tremendous amount of space between the electrons and the nucleus. If all this empty space exists in matter, how can any substance be solid?

The impact of natural disasters is made vivid in this video segment adapted from NOVA. A small town in Iceland, prepared for recurrent avalanches, is devastated when one takes a new and damaging path.

This webpage from Exploratorium provides an activity that demonstrates the Bernoulli principle with readily available materials. In this activity a table tennis ball is levitated in a stream of air from a vacuum cleaner. The site provides an explanation of what happens, asks questions about the activity, and also describes applications to flight. This activity is part of Exploratorium's Science Snacks series.

In this quick and simple activity, learners explore how the distribution of the mass of an object determines the position of its center of gravity, its angular momentum, and your ability to balance it. Learners discover it is easier to balance a wooden dowel on the tip of their fingers when a lump of clay is near the top of the stick. Use this activity to introduce learners to rotational inertia.

Experiment with a helium balloon, a hot air balloon, or a rigid sphere filled with different gases. Discover what makes some balloons float and others sink.

Students explore static electricity by rubbing a simulated balloon on a sweater. As they view the charges in the sweater, balloon, and adjacent wall, they gain an understanding of charge transfer. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). The simulations are animated, interactive, and game-like environments.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

In this video from DragonflyTV, Jai and Jonathan track, graph, and analyze the motion of basketball shots as they investigate what factors influence the accuracy of their game.

Look inside a resistor to see how it works. Increase the battery voltage to make more electrons flow though the resistor. Increase the resistance to block the flow of electrons. Watch the current and resistor temperature change.

Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.

Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.

This video segment describes how the Australopithecus afarensis skeleton known as Lucy could have been fossilized. Footage courtesy of NOVA: "In Search of Human Origins."

When you spin it around, this toy sounds like a swarm of buzzing bees.

Demonstrate the Bernoulli Principle using simple materials on a small or large scale. This resource includes two activities that allow learners to experience the Bernoulli Principle, in which an object is suspended in air by blowing down on it. Use this activity to explain how atomizers work and why windows are sometimes sucked out of their frames as two trains rush past each other.

Watch beta decay occur for a collection of nuclei or for an individual nucleus.