Games that have scoring, such as throwing balls into a basket, require children to count. Introduce games such as dominoes or rolling dice. Have your child roll the dice and count the dots. Let her try to roll for matches. Count favorite toys.
Books often have number themes or ideas.
Next time you take a car trip with your preschooler, look for other opportunities to introduce math concepts to your preschooler. Reading numbers off of license plates, road signs or advertisements. Looking for shapes of different colors. I see a big blue square. Inc. Other trademarks property of their respective holders.