Tellegami seems to be a perfect forum for Common Core Modules. In third grade Module 4 requires students to create a public service announcement for importance of clean water for everyone. Students could outline the reasons clean water is necessary (potable water, health/sanitation, and farming) then write a PSA script for Tellegami avatar. Lastly, students would actually go to site and create PSA.
In 4th grade, Module 4 requires a PSA on the importance of voting. Again, students would brainstorm main points and then write the script. The 30 second, 450 character limitation forces the student to convey only the main idea or salient points. Initially, 30 seconds may not seem like a long time but as with all things, conveying a message in a meaningful and engaging way is probably harder than it seems. Reviewing and analyzing actual PSAs would help students reflect not only on the message itself but how the style and language affects the message.