Skip to main content Skip to main navigation Skip to footer
Login
Student Login
Educator Login
Sign Up For Free
Gizmos home page Gizmos home page
Gizmos home page
  • Find Gizmos
    
                                                
    See Full Search Results
    • FREE Gizmos
    • NEW Releases
    • STEM Cases
    • Browse by Standard
    • Browse by Grade & Topic
    • Browse by Core Curriculum
  • About Gizmos
    • What's a Gizmo?
    • About STEM Cases
    • What are Gizmos Investigations?
    • Take a Tour
    • Supporting All Students
    • How to Get Gizmos
    • Testimonials
    • K-5 Science
  • Research
    • The Impact of Gizmos on Student Achievement
    • The Research Behind Gizmos
  • Support
    • Professional Development Overview
    • Meet the Team
    • Course Catalog
    • Help Center
    • Site Status
  • Resources
    • Popular Gizmos Collections
    • Educator Resource Hub
    • Success Stories
    • Insights
  • Get More Info
    • Sign Up for Free
    • Request Purchasing Info
    • Request a Demo
    • Request a Pilot
    • Contact Support
  • Login
    • Student Login
    • Educator Login
  • Sign Up For Free
  • Home
  • Find Gizmos
  • Browse by Core Curriculum
  • Holt Textbooks
  • Holt Science & Technology: Red (2006)

Holt Science & Technology: Red (2006)

4: The Cell in Action

Screenshot of Cell Energy Cycle

Cell Energy Cycle

Explore the processes of photosynthesis and respiration that occur within plant and animal cells. The cyclical nature of the two processes can be constructed visually, and the simplified photosynthesis and respiration formulae can be balanced. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Diffusion

Diffusion

Explore the motion of particles as they bounce around from one side of a room to the other through an adjustable gap or partition. The mass of the particles can be adjusted, as well as the temperature of the room and the initial number of particles. In a real-world context, this can be used to learn about how odors travel, fluids move through gaps, the thermodynamics of gases, and statistical probability. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Osmosis

Osmosis

Adjust the concentration of a solute on either side of a membrane in a cell and observe the system as it adjusts to the conditions through osmosis. The initial concentration of the solute can be manipulated, along with the volume of the cell. 5 Minute Preview


Lesson Info
Launch Gizmo

11: Adapting to the Environment

Screenshot of Natural Selection

Natural Selection

You are a bird hunting moths (both dark and light) that live on trees. As you capture the moths most easily visible against the tree surface, the moth populations change, illustrating the effects of natural selection. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Pollination: Flower to Fruit

Pollination: Flower to Fruit

Label a diagram that illustrates the anatomy of a flower, and understand the function of each structure. Compare the processes of self pollination and cross pollination, and explore how fertilization takes place in a flowering plant. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Rainfall and Bird Beaks

Rainfall and Bird Beaks

Study the thickness of birds' beaks over a five-year period as you control the yearly rainfall on an isolated island. As the environmental conditions change, the species must adapt (a real-world consequence) to avoid extinction. 5 Minute Preview


Lesson Info
Launch Gizmo

12: Interactions of Living Things

Screenshot of Food Chain

Food Chain

In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Plants and Snails

Plants and Snails

Study the production and use of gases by plants and animals. Measure the oxygen and carbon dioxide levels in a test tube containing snails and elodea (a type of plant) in both light and dark conditions. Learn about the interdependence of plants and animals. 5 Minute Preview


Lesson Info
Launch Gizmo

13: Cycles in Nature

Screenshot of Cell Energy Cycle

Cell Energy Cycle

Explore the processes of photosynthesis and respiration that occur within plant and animal cells. The cyclical nature of the two processes can be constructed visually, and the simplified photosynthesis and respiration formulae can be balanced. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Rock Cycle

Rock Cycle

Play the role of a piece of rock moving through the rock cycle. Select a starting location and follow many possible paths throughout the cycle. Learn how rocks are formed, weathered, eroded, and reformed as they move from Earth's surface to locations deep within the crust. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Water Cycle

Water Cycle

Control the path of a drop of water as it travels through the water cycle. Many alternatives are presented at each stage. Determine how the water moves from one location to another, and learn how water resources are distributed in these locations. 5 Minute Preview


Lesson Info
Launch Gizmo

14: The Earth's Ecosystems

Screenshot of Food Chain

Food Chain

In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview


Lesson Info
Launch Gizmo

15: Caring for Florida's Environment

Screenshot of Water Pollution

Water Pollution

Get to know the four main types of pollution present in the environment, and then look at a variety of real-world examples as you try to guess what type of pollution is represented by each situation. All of the real-world situations can be viewed every day in different parts of the world. 5 Minute Preview


Lesson Info
Launch Gizmo

16: Rivers and Groundwater

Screenshot of Porosity

Porosity

Pour water on a variety of sediment samples to find how much water can be absorbed by the sample (porosity) and how easily water flows through the sample (permeability). 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Water Cycle

Water Cycle

Control the path of a drop of water as it travels through the water cycle. Many alternatives are presented at each stage. Determine how the water moves from one location to another, and learn how water resources are distributed in these locations. 5 Minute Preview


Lesson Info
Launch Gizmo

18: The Movement of Ocean Water

Screenshot of Ocean Mapping

Ocean Mapping

Use a sonar on a boat to remotely measure the depth of an ocean at various locations. Describe multiple points on the ocean floor using their latitude, longitude, and depth. View maps of ocean depth in two and three dimensions, and use these maps to plot a safe route for ships to follow. 5 Minute Preview


Lesson Info
Launch Gizmo

19: Studying Space

Screenshot of Comparing Earth and Venus

Comparing Earth and Venus

Observe the motions of Venus and Earth as the planets move around the Sun. Measure the length of a day and a year on Earth and Venus, and compare the length of a solar day to the length of a sidereal day. 5 Minute Preview


Lesson Info
Launch Gizmo

21: The Properties of Matter

Screenshot of Density Laboratory

Density Laboratory

With a scale to measure mass, a graduated cylinder to measure volume, and a large beaker of liquid to observe flotation, the relationship between mass, volume, density, and flotation can be investigated. The density of the liquid in the beaker can be adjusted, and a variety of objects can be studied during the investigation. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Mystery Powder Analysis

Mystery Powder Analysis

Perform multiple experiments using several common powders such as corn starch, baking powder, baking soda, salt, and gelatin. The results of the research on the known powders can then be used to analyze several unknowns using the scientific method. The unknowns can be a single powder or a combination of the known powders. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Phase Changes

Phase Changes

Explore the relationship between molecular motion, temperature, and phase changes. Compare the molecular structure of solids, liquids, and gases. Graph temperature changes as ice is melted and water is boiled. Find the effect of altitude on phase changes. The starting temperature, ice volume, altitude, and rate of heating or cooling can be adjusted. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Temperature and Particle Motion

Temperature and Particle Motion

Observe the movement of particles of an ideal gas at a variety of temperatures. A histogram showing the Maxwell-Boltzmann velocity distribution is shown, and the most probable velocity, mean velocity, and root mean square velocity can be calculated. Molecules of different gases can be compared. 5 Minute Preview


Lesson Info
Launch Gizmo

22: Forces and Work

Screenshot of Fan Cart Physics

Fan Cart Physics

Gain an understanding of Newton's Laws by experimenting with a cart (on which up to three fans are placed) on a linear track. The cart has a mass, as does each fan. The fans exert a constant force when switched on, and the direction of the fans can be altered as the position, velocity, and acceleration of the cart are measured. 5 Minute Preview


Lesson Info
Launch Gizmo
Screenshot of Pulley Lab

Pulley Lab

Use a pulley system to lift a heavy weight to a certain height. Measure the force required to lift the weight using up to three fixed and three movable pulleys. The weight to be lifted and the efficiency of the pulley system can be adjusted, and the height of the weight and the total input distance are reported. 5 Minute Preview


Lesson Info
Launch Gizmo

23: Forces in Fluids

Screenshot of Archimedes' Principle

Archimedes' Principle

Place weights into a boat and see how far the boat sinks into a tank of liquid. The depth of the boat can be measured, as well as the amount of liquid displaced. The dimensions of the boat and the density of the liquid can be adjusted. See how much weight the boat can hold before it sinks to the bottom! 5 Minute Preview


Lesson Info
Launch Gizmo

How Free Gizmos Work

Gizmos icon

Start teaching with 20-40 Free Gizmos. See the full list.

Lesson materials list icon

Access lesson materials for Free Gizmos including teacher guides, lesson plans, and more.

Time icon

All other Gizmos are limited to a 5 Minute Preview and can only be used for 5 minutes a day.

Refresh icon

Free Gizmos change each semester. The new collection will be available January 1 and July 1.

Sign Up for Free

About STEM Cases

Students assume the role of a scientist trying to solve a real world problem. They use scientific practices to collect and analyze data, and form and test a hypothesis as they solve the problems.

Realtime reporting icon

Each STEM Case uses realtime reporting to show live student results.
Introduction to the Heatmap

Time icon

STEM Cases take between 30-90 minutes for students to complete, depending on the case.

Save icon

Student progress is automatically saved so that STEM Cases can be completed over multiple sessions.

Grades icon

Multiple grade-appropriate versions, or levels, exist for each STEM Case.

Handbook icon

Each STEM Case level has an associated Handbook. These are interactive guides that focus on the science concepts underlying the case.

STEM Case Help & Resources Sign Up for Free

Want More?

Check out these quick links.

  • Sign up for a FREE Trial!
  • Take a Tour
  • Get Help

Find Your Solution

Start playing, exploring and learning today with a free account. Or contact us for a quote or demo.

Sign Up For Free Get a Quote
Find Your Solution
Gizmos logo Brought to you by ExploreLearning

© 2025 ExploreLearning. All rights reserved. Gizmo and Gizmos are registered trademarks of ExploreLearning. STEM Cases, Handbooks and the associated Realtime Reporting System are protected by US Patent No. 10,410,534

Other Products

Reflex icon Frax icon Science4Us icon
Find Gizmos
  • FREE Gizmos
  • NEW Releases
  • STEM Cases
  • Browse by Standard
  • Browse by Grade & Topic
  • Browse by Core Curriculum
About Gizmos
  • What's a Gizmo?
  • About STEM Cases
  • What are Gizmos Investigations?
  • Take a Tour
  • Supporting All Students
  • How to Get Gizmos
  • Testimonials
  • K-5 Science
Research
  • The Impact of Gizmos on Student Achievement
  • The Research Behind Gizmos
Support
  • Professional Development Overview
  • Meet the Team
  • Course Catalog
  • Help Center
  • Site Status
Resources
  • Popular Gizmos Collections
  • Educator Resource Hub
  • Success Stories
  • Insights
Get More Info
  • Sign Up for Free
  • Request Purchasing Info
  • Request a Demo
  • Request a Pilot
  • Contact Support

Get Connected

  • Support Form
  • Toll-Free 866-882-4141
  • Local +1-434-293-7043
  • Newsletter Sign-Up
  • Facebook
  • Twitter
  • YouTube
  • Instagram

Other Products

Reflex icon Frax icon Science4Us icon

© 2025 ExploreLearning. All rights reserved. Gizmo and Gizmos are registered trademarks of ExploreLearning. STEM Cases, Handbooks and the associated Realtime Reporting System are protected by US Patent No. 10,410,534

  • Terms and Conditions
  • Privacy Policy
  • Accessibility
  • System Requirements
  • Sitemap