Mathematics Resources for Elementary Students

FunBrain number exercises. The site is full of fun for kids.
Fourth grade math
Online arithmetic calculator  
First grade math
Flashcards math for kids. The site has interactive exercises with instant feedback.
You can even time yourself.
Fifth grade math
Multiplication table
Kindergarten math
Second grade math
Kidsmath. The site has interactive exercises with instant feedback.
Ask Dr. Math for elementary level grades
Third grade math
K-5 math
Consumer math for K-8 
Math activities for K-4
Basic math
Online calculators. The site has 13 different kinds of calculators.
Math for all levels
Help with basic math skills
Math dictionary for kids
Fractions  
Decimal Place Value