Sounds like he memorized what you wanted to hear. He has not conected what the numbers mean. For Math issues, I use M&M's, Jelly Beans, Skittles or other small candy. Draw on notecards from 1 to 10. Pick random numbers between 1 and ten and have him put the candies on the correct card. For example, ask him what three means, then have him count out 3 candies, then find the correct card to associate it with. After he has all 10 correct, let him have the candies for a reward.
After playing for a few days, change it up and have him write out the number on the card it belongs to. I sometimes help by placing dots in the shape of the number to help with pencil control. After a few times of that, don't give him clues and see how he does. It will take a few weeks, a big bag of candy, and you have to make time to play each day.
I used this method with explaining base ten also. Using a small container that overflows after ten candies,expalin it belongs to the next tube if you want to get any more candy (ten's place) and the counting begins again.
I still remember in Kindergarten when my light bulb went off after I found out the letter "LMNOP" was 5 different letters, I always thougt it was one really long sounding letter like W (you do squish it all together when you sing the song!).
Good luck. I was always successful with my daycare kids and my own using the above method. All of them are in Advanced Math now.