While on a long car trip pick one thing to count along the way such as animals or gas stations. Put a puzzle together. Have your child set the table and count aloud the number of plates, cups and utensils. Go on a family bike ride and count the number of dogs you see along the way. Have your child estimate how long they are and then check the predictions by measuring each object together.
Older children can learn fractions by finding things three times or half as long.
Have your child count the number of stop signs or traffic lights between your home and the park. Give your child a jar of coins. Help her sort them and try to learn what each is worth. Present your child with two different objects. Have her guess which is the heaviest and then weigh them and compare.