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.
Math worksheets don't provide immediate feedback _ Most teachers are familiar with the long delay between when students complete a worksheet, and when they get their correct page. Most don't get anything back until the next day or the next week. In the meantime, the students continue to practice incorrectly. It's no surprise that immediate feedback has been shown to increase student performance and diligence. Unfortunately, math worksheets have no mechanism for keeping a student from moving to the next problem until after they demonstrate understanding. Good curriculum software can address this issue by giving students instant responses and strategic feedback. The use of visual cues and auditory feedback helps students quickly recognize their fraction errors and self_correct. This just_in_time feedback system eliminates practicing incorrectly, while promoting self_correction and independence.