In order to develop a student that has good math skills, a parent must play a key role in the learning process. In addition to parents, teachers and other family members are very important to a child's mathematical development.
I have observed teachers who really challenge their students to achieve higher order thinking These teachers take their students as early as the Second Grade and teach them how to add, subtract, multiply and divide using only their bran. We call this Mental Math. When I observed a Second Grade Class that had their students mentally answering math computation questions, I put my own son in that class. Shortly after being enrolled, He, too, learned how to do Mental Math. From that point on, math was my son's best subject. Teachers can really make a difference and parents can help affect change.
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!
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.