Students in public school were assigned to write in Arabic the Shahada (Testimony of Faith), not in Tennessee, but in neighboring Virginia.
In English, it is:
I bear witness that there is no God except Allah;
And I bear witness that Muhammad (peace be upon him) is His servant and messenger
This occurred in 9th grade World Geography class at Riverheads High School, Augusta County, Virginia, December 11th, 2015.
See for example the Washington Post article Schoolwork about Islam triggers backlash in Virginia county and Parents in Augusta County Concerned About Islamic Indoctrination
The above assignment was taken by the teacher, Cheryl LaPorte, from page 122 of the book World Religions by Gabriel Arquilevich.
Laurel Truxell and others were pressured to pose in Hijab for the yearbook by the same teacher (Cheryl LaPorte):
the teacher pushed and pushed and pushed so I did it, and when she took a picture, I asked for it not to be in the yearbook and she said it was, so that's when my parents called the school
As far as the Tennessee situation, we do not have a written copy of a particular assignment; however, the corresponding state standard required that students:
7.6 Explain the significance of the Qur’an and the Sunnah as the primary sources of Islamic beliefs, practice, and law and their influence in Muslims’ daily life.
What happened is explained in Maury parents angered over Islam unit. 7th graders at Spring Hill Middle School, Maury County, were required to learn the 5 pillars of Islam. This involved classwork and assignments that necessitated writing and verbally stating the Shahada in English.
students were instructed to write, “Allah is the only God,” said parent Brandee Porterfield.... the teacher verbally asked students about the five pillars, “And the students were reciting the Shahada.”
...
My child was required to write ‘Allah is the only God’, parent Joy Ellis said
However, after a meeting:
Principal Shanda Sparrow said students would not have to write the Shahada again.
Director of Schools Dr. Marczak released a written statement acknowledging that:
For this last section on the Islamic World this past week, our educators had students complete an assignment that had an emphasis on Islamic Faith. The assignment covered some sensitive topics that are of importance to Islamic religion and caused some confusion around whether we are asking students to believe in or simply understand the religion.
The state of Tennessee has recently (September 2016) revised its standard for 7th grade as explained in Islam removed from draft Tenn. 7th grade social studies standards:
gone is a standard about understanding the Qur’an and Sunnah