Students determine the mass and volume of soil samples and calculate the density of the soils. They use this information to determine the suitability of the soil to support a building foundation.

This demonstration shows that an increase in temperature will speed up the water cycle. One outcome will be an increase in rainfall. A second outcome will be the increase in total evaporation of water and subsequent drought. Materials required include two aquariums, plastic wrap, 2 clamp lamps with 60 watt light bulbs, pebbles and rocks, modeling clay, blue food coloring, and water. Student worksheets, background information for teachers, and a scoring rubric are included. This is Activity 2 in Too Many Blankets, a module in the lesson series, Potential Consequences of Climate Variability and Change.

Students learn that it is incorrect to believe that heavier objects fall faster than lighter objects. By close observation of falling objects, they see that it is the amount of air resistance, not the weight of an object, which determines how quickly an object falls.

This task is designed as an assessment item. It requires students to use information in a two-way table to calculate a probability and a conditional probability. Although the item is written in multiple choice format, the answer choices could be omitted to create a short-answer task.

This is a lesson about the distance to Saturn. Learners will use simple props to create a playground model for size and distance for the Sun, Earth, and Saturn ‰ÛÓ then walk on their scale model to Saturn. Writing activities engage students in reflecting on experience and in comparing and contrasting. This is lesson 4 of 12 in the Mission to Saturn Educators Guide, Reading Writing Rings, for grades 3-4.

While learning about volcanoes, magma and lava flows, students learn about the properties of liquid movement, coming to understand viscosity and other factors that increase and decrease liquid flow. They also learn about lava composition and its risk to human settlements.

Students practice their multiplication skills using robots with wheels built from LEGO® MINDSTORMS® NXT kits. They brainstorm distance travelled by the robots without physically measuring distance and then apply their math skills to correctly calculate the distance and compare their guesses with physical measurements. Through this activity, students estimate parameters other than by physically measuring them, practice multiplication, develop measuring skills, and use their creativity to come up with successful solutions.

Students measure the permeability of different types of soils, compare results and realize the importance of size, voids and density in permeability response.

In this activity using a balance scale students practice weighing items to see how heavy they are. Cubes are used in the balance as units of measure so students may easily count them.

Students work in pairs to measure length by lining up cubes along the longest side of an item. They count and record length by counting the number of cubes.

This task uses student generated data to assess standard 7.SP.7. This task could also be extended to address Standard 7.SP.1 by adding a small or whole class discussion of whether the class could be considered as a representative sample of all students at your school.

The purpose of this task is for students to apply the concepts of mass, volume, and density in a real-world context. There are several ways one might approach the problem, e.g., by estimating the volume of a person and dividing by the volume of a cell.

These two fraction division tasks use the same context and ask ŇHow much in one group?Ó but require students to divide the fractions in the opposite order. Students struggle to understand which order one should divide in a fraction division context, and these two tasks give them an opportunity to think carefully about the meaning of fraction division.

This task gives children an opportunity to subtract a three-digit number including a zero that requires regrouping. The solutions show how students can solve this problem before they have learned the traditional algorithm.

This is a lesson about representative sampling. When given parts of the Hubble Deep Field image, learners will count the number of galaxies in one sample section of the image. Then, they will calculate how many galaxies there are in each whole image and how many objects the Hubble Space Telescope could see in the entire Universe. This is Activity H-6 of Universe at Your Fingertips 2.0: A Collection of Activities and Resources for Teaching Astronomy DVD-ROM, which is available for purchase.

This is a mathematical modeling task aimed at making a reasonable estimate for something which is too large to count accurately, the number of leaves on a tree.

In this problem, the variables a,b,c, and d are introduced to represent important quantities for this esimate: students should all understand where the formula in the solution for the number of leaves comes from. Estimating the values of these variables is much trickier and the teacher should expect and allow a wide range of variation here.

This task requires students to find linear equations with different numbers of solutions.

The purpose of this task is to help students see the connection between aÖb and ab in a particular concrete example. The relationship between the division problem 3Ö8 and the fraction 3/8 is actually very subtle.