The same general idea worked when it came to my son's Lego's! It was a great way to work on patterns and following directions! I would draw a pattern on paper for him to copy and recreate with his Legos. It not only helped with his color recognition, but his problem solving skills, fine motor skills and he didn't even know he was doing math!!
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.
There was a time that the United States of America had some of the highest mathematic scores in the world for students in grades k through 12. A lot has changes since those days, and in order to help children get back on the path to being good mathematical students parents need to play an important role.
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!