The addition, subtraction & number counting worksheets are meant for improving & developing the IQ skills of the kids, while English comprehension & grammar worksheets are provided to skill students at constructing error free sentences.
Another strategy involves allowing your child to spend some time on a computer playing math games. The computer can be a wonderful resource that supports math and other subject area skills. Software is available that will measure a child's math skill level.
While the newer method does require computer access for every child, most schools now have that capability. As children do more hands-on learning on computers and less in books, these programs are capable of reaching them on a level they can understand.
Use things around the house that they already know and love! : My son has a HUGE adoration for his Thomas Trains... he can tell you every single trains name, number and color. When we started working on recognizing numbers and colors, I tried to use posters, games, workbooks, etc that would help him learn to recognize them... all to no avail! One day, we were playing with his trains, and HE asked me what number one of the trains was. Bells went off in my head and I realized that I could cater his natural curiosity about his beloved trains, and still be 'teaching' him to recognize numbers at the same time!