Keep math books and games around the house. Purchase, or borrow from friends, games that involve patterns and counting – any game with dice will work – or buy math-centric learning games for your child to play on his hand-held video game device. Allow him to play these video games at times when video games would normally be off-limits; he'll be so thrilled to be able to use his device, he'll be willing to spend the time doing math.
Talk about math while doing tasks around the house. Ask your child's help in solving problems. Think out loud when you're at the grocery store together. Say things like “I only have $5 to spend on beans. How many cans can I buy for $5?” or list the prices of several items in your cart and ask your child to help you add them up. Count passing cars out loud to help a younger child learn.
Help with her homework -- or find someone else who can. If she doesn't understand a problem or concept, she'll get overwhelmed and frustrated. Explain the necessary steps to solving a problem in simple terms, or hire a math tutor to help her; she'll like the subject much better if she experiences the satisfaction of finding the right answer.
Use food or props he likes to demonstrate math concepts he's learning in school. Bake a pizza and cut it into a dozen pieces to demonstrate fractions, or buy bulk candy or a huge bunch of grapes and use them to demonstrate multiplication. Let him snack on the leftovers once he's finished learning.
Arrange a meeting with someone who has a career your child finds exciting. Ask that person to explain how she uses math in her work. Ask a chef to explain how important it is to be able to measure ingredients or use multiplication when doubling recipes, or ask a firefighter or doctor to tell your child about the ways he uses math.