Science
Grade 1 Animal Nation
Grade 2 Amazing Animal Adaptations
Grade 2 Hey, Little Ant
Grade 2 How Does Your Garden Grow
Grade 3 Design a Garden
Grade 3 Wildlife Protection Program
Grade 3 How to Feed the Community
Grade 4 Enigmas
Grade 5 Energy Efficiency Exploration
Grade 5 Toys That Matter
For only $35, you become a member for life! This means you have access to all their curriculum, books, STEM materials and kits for the rest of your teaching career. My only complaint is that the site is very poorly organized and difficult to navigate. However, they are more than happy to help via email and respond quickly. Absolutely worthwhile.
Slideshow for their 3rd/4th grade curriculum to help you get started! (You'll need a membership to see the content of these lessons, but this organized all of them for you, adds videos, and more!)
Students try to improve and old, outdated zoo while learning to research and learn more about animals along the way. It culminates in a research and model zoo exhibit project and typically takes about 12-14 class sessions (45 minutes to 1 hour each).
A student favorite has been doing either Mystery Science: the Case of the Missing Bicycle (Grades 3-4) or Mystery Science: The Case of the Missing Lunch followed by some wonderful activities from this CSI site. Some activities needed a little scaffolding, but they were wonderful at giving students a glimpse of what real detective do, even the not-so-fun stuff like staying within budget when running tests. You could honestly do a whole unit from the site alone, and students would love it!