In many second grade classrooms, students will be writing opinion pieces with the focus on persuasive reviews! Right away most of us think about book reviews. However, I would urge you to go further than that. What about movies, places they have traveled or would like to travel, or restaurants. One student I worked with decided to write about a favorite restaurant of her family. The teacher then sent the review to that restaurant. What a surprise when the student received a gift certificate from the restaurant AND was told that they framed the review and hung it by their door! So, don't just limit the writing, challenge the students to write for REAL reasons!
A book that I like to use for support and ideas is Is That a Fact? by Tony Stead. His chapter on persuasive writing has examples and structure for K-3 students. He suggests doing a travel brochure together as a class. You might want to gather some brochures about one certain place and let the children investigate them in groups. Making a chart of what they learned about their special place, will give them the materials they need. You will then record it as a class in a shared writing.
Another idea he shared was to ask the children to look in those brochures for words and phrases that they felt were persuasive. These words would also go onto a chart. After each workshop's focus lesson, the students would work as partners or groups to develop their own brochure. Later, lessons on revision and editing would also be included.
Don't forget to check out the All Write!!! website for a set of lessons on persuasion for K-1. These lessons focus on writing book reviews, but I am sure you could use them for movies, travel or restaurants. This could become your favorite unit of study!!!