There are some new materials being developed now based on what we are learning about how the brain learns. These brain_friendly materials should be an improvement over what has existed. I recently bought a book by Marcia L. Tate titled "Mathematics Worksheets Don't Grow Dendrites." I highly recommend her book. She gives a great deal of information on alternative activities that are better for your child's brain development and for learning.
There are many math_based games available in educational toy stores that will help to reinforce the principles your child learns in worksheets. Computer games can help too, but depending on the age of your child, it is best not to encourage too much computer use at an early age. Everyday activities can be turned into math lessons too. A trip to the grocery store can turn into a math lesson if you encourage your child to help you count how many items you are buying, or add up the bottles of milk as you add them to your cart.