The Piggy Bank Game
You can use a piggy bank if you have one you cannot see through and has a way to easily open up the bottom and reseal it again. If you don't have one, just take a 1/2 gallon milk carton and cut it in half. Wash out the bottom half and throw the top part away. You can cover the milk carton half with contact paper or the like if you wish. Turn it over so that the bottom part is now the top and cut a slit wide enough so that whatever you are using as counters can fit. I like using pennies. Put the box on the table, with the open end on the table and the end with the slit in it up. Drop whatever number of counters you want into the box through the slit as the child counts aloud. Ask him how many does he think will be on the table when you lift the box. Lift the carton and count together.
Spill The Beans
This is best played in a group, so I usually like playing this game just as everyone is sitting down to dinner. It only takes a minute. All you need for this game is a bag of beans and a baggie. Counting aloud, place as many beans in the bag as appropriate. Pass the bag around a group until you stay stop, stopping it at the child(ren) that you want to have this practice. Ask the child who has the bag to predict how many will be in the bag, and then have him spill the beans onto the table and we again count aloud.
Another game that is fun to play just before dinner. Standing up behind the chair at the table, everyone counts off in turn and then sits down as he says his number. When the last child sits down, the whole group says this number. You can do this however many times you feel is helpful. Ask the child who is working on this skill what he thinks will be the last number between each time.