CK-12 Foundation
Ck 12: Elem Math: Areas of Rectangular Composite Figures Challenge:word Problems
[Free Registration/Login may be required to access all resource tools.] A learning module where students solve multi-step word problems involving money and the area of rectangles. A video shows how to solve a sample problem. [2:21] A set...
National Council of Teachers of Mathematics
The Math Forum: Calculation Tips & Tricks: Multiplication Tips
Find tips for multiplying by 5, 9, and 11, and learn how to solve math problems without a calculator. This site includes explanations and examples for gifted children and teachers wanting to challenge their students.
abcteach
Abcteach: Number Puzzles
[Free Registration/Login Required] Solve the number puzzles as you practice basic addition skills and improve your number sense. The site has challenging activities with varying levels of difficulty.