Does your kid have solid basics in math?
It is tough to go forward on math if your kid has very weak basics. Can he memorize multiplication table inside out? Can he do multi digit multiplication and division like a piece of cake? If not, you better find some help for him! More advanced math (algebra, etc.) is built on top of basics. Without knowing basic stuff inside out, it would be tougher and tougher for him to figure out what is going on.