This is an activity that my son enjoyed a lot, so I thought I would share. We started using this when he was five years old, doing kindergarten work. He could count by fives perfectly, but I wanted to make sure that he could recognize the numbers as well. I printed out the numbers 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 fairly large on cardstock paper. I then cut them into little squares. I gave them to him all mixed up, and had him put them in the correct order. For beginning learners, you can start with half of the numbers, and then add the second half once your child gets those down. I cannot stress how helpful this is when learning about money, and counting nickels! We coincidentally did this shortly before the "nickels" section in his time and money book came up.
We also used the same concept with recognizing the months and days of the week. Simple enough, and it's fun, too!