Each student will need their own Student Workbook for each of the four sets (1-7, 8-15, 16-22, 23-30). If you purchase the complete set of each volume, one workbook will come with the set. Each student will also need their own Spelling Journal - this is a one time purchase for the entire length of the Essentials program and one copy will come with the complete set.
Many teachers/parents find it helpful for each student to have their own set of Phonogram Game Tiles to manipulate for the lessons. However, some students are fine sharing and working through the problems together with the same game tiles. Students do NOT need their own game cards as up to four students can play with the same set of game cards.
If you will have multiple students completing activities from the Essentials Reader, it may be helpful for each student to have their own reader (unless they can read at different times). And each student will need their own Student Activity Book.