I modeled every step of the way using our school nurse as my example. This type of writing was very new for my kids, so I had them work in groups. (Sidenote-They all freaked out when I said the word essay.)
Day 1: Choose your central idea and support
I gave each group a 12x18 piece of construction paper that was folded into four sections. They had to write their central idea and three meaning reasons to support it.
You will have to have a conversation about why "She is nice" is not meaningful support. I told my students that our nurse had long hair, was from Kansas, and was nice, but that had nothing to do with why she was important to our school.
Day 2: Plan your support
•What ifs (what if that person wasn't at our school? What would happen?)
We planned how we would support each reason.
Day 3: Time to write!
Needless to say, writing their paragraphs was a breeze after all that planning. Each kid in the group chose a reason to turn into a paragraph, and they whipped out an expository essay in no time.
I was so happy with how these lessons went. Each day my room was loud, but it was the GOOD kind of loud. Kids talking and planning and discussing writing! Swoon.