Here are five websites that offer free educational material for Primary and Secondary students.

Free puzzlemaker:  http://www.discoveryeducation.com/free-puzzlemaker/?CFID=1837424&CFTOKEN=4101428...
Free Preschool and Kindergarten Worksheets:  http://www.kidslearningstation.com/
Free English/Language Arts Worksheets:  http://www.tlsbooks.com/englishworksheets.htm
EZ School Subjects - English:  http://www.ezschool.com/subjects.html
Tutorial World :  http://www.tut-world.com/index.html

Each site offers free downloads of material for students.
Example:
Vocabulary (1.1) Primary 6

Write the number of the correct answer in the brackets.
                                   
1.      This is an excellent science magazine, you should ________ to it.
     (1)      order      (3)      subscribe
     (2)      purchase      (4)      charge      (      )

2.      You need a doctor's ________ to buy this medicine.
     (1)      certificate      (3)      prescription
     (2)      letter      (4)      order      (      )

Have fun!