I haven't done centers since before Christmas and now I'm at a loss as to what to do. Any ideas? Any ideas will help but I'm looking for a center idea using the calculator and another for word problems.

Have you taken a look at this book? Math Centers Grades 3-4 (Take It to Your Seat) by Jo Ellen Moore http://www.amazon.com/Math-Centers-Grades-Take-Your/dp/1557999791

To use an idea from Everyday Math. There is a game called "Beat the Calculator." It is a game in partners (or triplets.) For partners- One person flips a card with a math fact- The person with the calculator must type it in and get the right answer. The other person does it in their head and tries to "beat the calculator." They play a round of 10 facts then switch jobs. The facts can be anything, addition, subtraction, multiplication, division. At this point in the year most of my kids can beat the calculator for their facts. They keep the cards they win. I have some old flashcards that I shuffle up to use for this. With a triplet one person is the calculator, one is the brain, and one is the fact caller. Then switch jobs every 5 facts.

Ooh! I just started using math centers, and I love them! Here's an idea for word problems. Write out problems on big sheets of paper, only in every place where there should be a number, just trace a square for a Post-It note. The kids can stick their own numbers on there and solve the problems. I haven't tried this yet in centers, but I do it myself for bellwork. I write out some tough word problems, and use them over and over. At first, many students have trouble with the problems (I use the ones missed most often on tests), but once they get the concept, it doesn't matter what numbers I put in the slots. Once they learn how to solve the problem, they get the satisfaction of conquering that beast again and again.