I use this activity during my Daily 5 "Word Work" group. Students are given a "Root of the Week"... for example, prefix un-.
Students will then fill in the date, root, meaning, and draw a picture that will help them remember what the meaning of the root is.
After they've completed this portion, they will brainstorm with their small group words that go with this root. Once they have decided on which three words they would like to use, they will list them. Then they will each get a dictionary, look up the definition of the word, and write down the definition on their paper.
Lastly, students will use each of the words they choose in a sentence at the bottom.
I use this as a word work/spelling/writing classwork grade (weekly).