Build number recognition by sharing counting books together every day. Chose simple counting stories such as Eric Carle's "The Very Hungry Caterpillar." Read books of simple counting songs. Try "This Old Man" by Carol Jones. Make sure reading and singing together is fun. Be enthusiastic and enjoy this special time with your child.
Talk about numbers. Go out for a walk and point out all the numbers that you see -- on doors, on road signs, and on mail boxes. Look for the different numbers in the grocery store, such as in the produce aisle. Encourage your child to tell you what numbers he can recognize; have a competition to see who is first to spot the number "5," for example.
Look online for activity ideas to share with your child. Investigate the many age-appropriate computer math games that are available. Try the Scholastic website or Enchanted Learning as a starting point. Play these games with your child; try not to use them as a way of keeping her entertained while you do something else.
Have numbers around the house. Put some magnetic plastic numbers on the refrigerator door so that your child can see them and play with them. Consider investing in some large number tiles or some number posters to put on your child's wall.