Here’s another link, accessible to English Language Learners, where students can calculate the impact that they have on the environment.  Ecologic Games, through the use of symbols, pictures, and words, is an excellent site.

I have the link on my Science page.  There are other similar activities on different pages.  I try to be somewhat consistent in my categorization, but, as Ralph Waldo Emerson said, “A foolish consistency is the hobgoblin of little minds.”