Okta challenges you to a duel! That crazy octopus wants to play you in a game where the first person to choose cards with a specified sum wins. You can choose how many cards, what types of numbers, and Okta's level of strategy.

In this visualization adapted from the University of Massachusetts Medical School, discover the role that dengue viral proteins play in a human cell as the virus prepares to replicate.

Why do objects like wood float in water? Does it depend on size? Create a custom object to explore the effects of mass and volume on density. Can you discover the relationship? Use the scale to measure the mass of an object, then hold the object under water to measure its volume. Can you identify all the mystery objects?

Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.

In this lab activity, students determine density differences of water samples with varying temperature and salinity levels. Students synthesize information to predict the effects of oil in given water samples.

This is an integration of science leaf observations with musical composition for early elementary students.

This video segment from NOVA: A Desert Place describes the physical characteristics and organisms that define the desert biome.

This activity is a lab where students will design an experiment dealing with one of the five senses. Students will collect data outside of class, write a formal lab write up as well as a group presentation on their findings.

This interdisciplinary course is a real-world collaborative multi-year project that connects various departments, courses, and independent study projects on a college campus. Using the client/consultant model, students from several departments and a wide range of environmental backgrounds come together to explore the design of an efficient future student house on campus. Over a couple of years, students research and test building designs, energy for heating and power, natural flows of available energy, natural ecosystem processes including living machines, and possible materials to use in the eventual construction of the eco-house. This SERC Starting Point site includes learning goals, context for use, teaching tips and materials, assessment, and references.

This activity is a lab where students design an experiment to test the rate of photosynthesis. Students will analyze data,write a report using the scientific method, and apply results to current environmental issues.

This video from Nature offers a description of desirable traits in beef and dairy cattle.

In this activity, students will investigate how much chlorophyll is in olive oil using a Varnier Spectrometer. Students will measure and analyze the visible light absorbance spectra of three standard olive oils obtained from any supermarket: extra virgin, regular, and light.

This video segment from Greater Boston examines whether environmental toxins may be to blame for a rare skin disease.

In this video segment from Nature, learn about six different breeds of cattle.

This lab activity is a paper fossil dig where students discover skeletal characteristics of humans, primates and hominids and are asked to make a short oral presentation to the class.

The disappearance of bees will have tremendous impact upon the way we live according to scientists in this segment from Nature.

Students disassemble and analyze retractable pens. Through the process of "reverse engineering," they learn how the ink pens work.

In this 6-lesson unit, students use dominoes to explore four models of addition: counting, number line, sets, and balanced equations. They learn about the commutative property, the relation between addition and subtraction, the result of adding 0, and the concept of doubles. Students write story problems which involve the operation of addition and begin to memorize the addition facts. They represent addition in pictures. The various models of addition help students develop a rich conceptual schema for addition. Included are a Bibliography of Counting Books, student materials, questions for student and teacher reflection, assessment and extension ideas. [Suggestion: Use the alternate applet, Pan Balance - Numbers, listed as a Related Resource, rather than Pan Balance - Shapes, in Lesson 4.]

In this lesson plan from NCTM Illuminations students learn to add fractions with like and unlike denominators to make a sum of one. The lesson plan includes two games utilizing fraction cards (PDF) and a fraction bar chart (PDF), and an online game through Calculation Nation which is cataloged separately.

This video segment from NOVA: "The Shape of Things" follows the growth of a duck embryo, from a single fertilized egg cell to a complex, hatching duckling.