Using Percent Increase and Decrease to Think About Human Impact on Wildlife

I REALLY wanted to create a percent increase/decrease project about endangered animals to wrap up Unit 4 for my 7th graders. (I use the OUR Illustrative Mathematics curriculum). I spent a long time reading about different conservation efforts, searching for data, and even watching documentaries (highly recommend both Virunga and Jane Goodall: The Hope ) but the idea just didn’t come together for me. Math projects are hard. Virtual math projects are even harder.

So no project – but I did come up with this lesson that lets kids use percentages to learn about/explore/solve math problems about threatened animals. It was still an interesting way to close out the unit. One student even said, “This lesson made me realize that I think of math as just a class you take, but now I see that math can be used in the world.” I both love and hate that she said that. All materials are linked at the end, in case you want to modify it + try it out.

Part 1: Notice and Wonder Launch

I used the graphics from this Guardian article to begin the lesson. I explained what “biomass” means, let kids think, and then recorded their ideas while they shared out.

Afterward, I sent them to breakout rooms to look at some more graphics and share what they notice and wonder on JamBoards.

When we returned as a class, I chose a different group to share their responses for each image. Then I asked, “What is the gist of these graphics? What are they showing us?” A few kids shared and I said something along the lines of, “These graphics show that even though humans are a tiny percentage of life on Earth, we’re having a really big impact on wildlife.” Next I asked, “What are some of the ways that we impact the environment and affect wildlife?” Kids shared (habitat destruction, climate change, our growing population, more cities/towns/houses, farmland for raising food and meat) and then I shared some information about the rates of extinction and the idea of wildlife conservation as well as the lesson goal: We’re going to use what we know about percents to study 4 animals who have been impacted by humans: mountain gorilla, tigers, desert tortoises, and island foxes.


Part 2: Background Research

Students split up into groups and quickly created slideshows about the 4 focus animals. I always feel guilty when kids aren’t doing math in math class, but I decided this was worth doing to build investment and background knowledge. I showed them an example about Pacific walruses and gave them 10 min in breakout rooms…along with a template and resources. When they came back, a few groups presented.

Part 3: The math!

Kids worked on these problems. The data/stats are all real.

Part 4: Closing with takeaways

I asked kids to share one takeaway from the lesson. It could be something they wondered, realized, learned or changed their mind about. This is when the student said it made her realize math could actually be used in the world. Yay, but also, damn. There is a glaring need for more K-12 math to be more connected to the world. It shouldn’t be news to 7th graders that math can help us understand the world.


Please let me know if you find ways to improve this lesson! I’m pretty sure I will come back to this idea and try to rework it into an actual project for the next batch of kids.

All materials here:

Presentation slides for the whole lesson.
Part 1: Notice and Wonder JamBoard.
Part 2: Google slides for group research.
Part 3: Math problems

Always happy to hear from readers!