At KidsKonnect, we create worksheets specifically for elementary school students up to grade/year 6. If you are looking for other educational material, you may wish to check out some of our other sites.
Exampapersplus.co.uk is a great source for UK exam prep material, especially for 11+ Exam Practice Papers.
Pretestplus.co.uk provides online practice tests for CAT4, ISEB Pretest, CEM Select and UKiset assessments.