My son is 6 now.
Just after he turned 5, i bought him sum swamp and he loved it. We played a lot. then I bought a game from Lakeshore Learning (pop to win, 1st grade). I am glad I didn' t buy the kindergarten version, it was too easy. Then I bought 3 packs of math cards from amazon and used it with that game.

What other math board games do you suggest? Should i just buy some more math cards ... I saw there was a discontinued game called Flip 4. Sounds interesting but I don't want to spend $20 if it's not really worth it. For reference, my son can
do mental math quite well like 42+35... and knows the concept of multiplication...