Anything less could cause children to suffer a tremendous loss. The teacher that parents should be trusting to teach their child math is a person that will challenge their child regardless of their age. In addition to the challenges, the teacher should encourage children to try hard. Children need to know that their teacher cares about them and is not just trying to give them a lot of hard work.
Go Shopping! : You can cater this to all different ages. For young children, you can do a 'mock shop' and let them pretend to go shopping in a pretend store (your kitchen). Label certain items with easy to read prices and print some pretend money for them to shop with! For older children, you can let them help you in the actual grocery store with a specific shopping list. You can even set specific spending limits and give a specific amount of items and let them determine what they can afford, etc.
Parents can assist with developing a lot of the fundamental skills needed for children to succeed in math when they attend school. Parents can do things that will support the schools and hopefully the schools will do the rest.
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.