Numbers in Kendergarten

You did not say how much he already knows so I will assume he needs to know all.

I would start with flash cards, you can make your own starting with 1 -10 and then move to 20 then 30.

Game: You could make 2 sets of the flashcards and practice making pairs and just saying the numbers as you find them. Maybe race to see who can find the most pairs.

As an online game: Try fisfer price count the score - its free and go to 20.
You might want to sit with him a few times when he does this. This is a simple click the mouse number pops up game so he will not get lost in other things.
http://www.fisher-price.com/us/fun/games/countthescore/de...

As he gets into numbers a lot just write the numbers one to 30 on a sheet of paper and go through them with him. By then he will be familiar with his numbers so this won't be hard when he sees them like this.

If you have a calendar in the house, use the month of March, it has 30 days, each day you both look at it and say day1, day 2 etc.

These are just some ideas. I think your goal is attainable for the end of the school year good luck.

We do flashcards and we practice on paper with her writing them and saying them. Repetition seems to be what works for us.

Everytime you see a number when you are shopping, out to eat, readign a book, have him tell you the number. When you start make sure you point out numbers that he can actually name, then gradually get harder.
Get those alphanumeric magnets and only put numbers on the fridge.
Do the 30 days song, 30 days hath September, April, June...... then use the calendar.
Make it fun for him.

Put numbers all over your house and make it a fun game to run around and find the correct number. I did that with my twins and we had a great time. I'd say let's find a 7 and if they found a number that wasn't 7 they'd tell me that's a 3 not a 7 and keep looking. Start off with numbers 1-10 and just keep adding them until you've gotten to 31.

We got some numbers and letters that stick to the tub (foam) and she learned them that way by putting them in order.

I wasn't going to answer your question because I didn't have any ideas for you, but I just read an article in the most recent Parents magazine, and they said that the best way for children to learn important pre-reading skills like recognizing letters and numbers is for their parents to read to them. So, I bet you could go to the children's section of your local library and ask the librarian to help you find books with those numbers in them, and s/he would find you something to get started with. Then if you read to him at least 20 minutes a day, I bet you'd see a big improvement in just a few weeks. Of course I don't know if/how much you read to him now, but I thought of your question when I read the article. Good luck!