I know this for a fact, in the business world people who are quick thinkers, problem solvers and critical thinkers have more success.
My children need to strain their brain, a lot! Math does that. Here are some places to find math word problems:
Word Problems For Kids
StudyGS.net (Scroll down a bit to the part that says Purple Math for the word problems– This one is good because it teachers you how to use algebra to solve the problem.
MathSurf.com~This site provides a 15 day list of word problems for elementary grades
Simple Word Problems for third and fourth grade~This is a PDF file from Saxxon Math