One of the first thing you can do with a young child is to try and incorporate basic math into day_to_day life. Children might find that studying math at school is not the most exciting thing, so it's your job to try and make it more exciting at home. There's a few simple ways you can do this that perhaps you'd never thought of before. One great way of getting your child involved with math at home is to let them help you with the cooking or baking. This is a perfect way to teach them about proportions, as they can help you decide how much of one ingredient needs to be used in comparison to another. Cooking can also help reinforce fraction skills as well a measurement when adding specific amounts of ingredients.
Teaching the subject to an older child may be a bit more difficult. There are many math problems out there that can be used to bring it down to their level. Using this subject in an everyday situation is a one idea. For example, tell a story that involves that child. If he goes to the store and buys a gallon of milk with a five dollar bill and the milk is only three dollars, how much money will he have left? Using word problems will help the child understand it more.