When trying to develop good math students, all avenues should be tried. Parents can make additional progress by allowing children to visit work locations that utilize a lot of math. Children should be exposed to as many careers as possible. Careers in math and even science should be on their list of considerations. Parents should inform children which careers require them to have good math skills.
The classes can be taught at the various colleges or universities in the local area. This is a community outreach for the colleges and universities, but children will develop social and academic skills that will carry over to their classroom and on to adulthood.
Sort it out! The sky is the limit when it comes to finding things to sort! Candy, beans, cotton balls, paper clips... you name it! You can even change around how you want it sorted... one time, sort by color, the next time sort by size or shape! My son had a BLAST when I pulled his Matchbox cars to the school table and we sorted them by color! For younger children, you can make it easier by having 'color cards' and have them match the specific objects to the correct card. Older children can just be told to sort out the items by color, shape, etc.
Elementary teachers and parents play the biggest role in a child's mathematical development, especially from Kindergarten through Fourth Grade. Time spent in school learning math or not learning math can never be replaced. Parents should make sure the elementary math teacher is knowledgeable and is a good teacher.