L + 1 is a key. In my private classes I am able to do that pretty well. The hardest thing about teaching in an elementary school is that there is no clear L (level). The level of the students is so mixed it is very hard to work out exactly what level to teach at. Go a bit difficult and you lose the lower level students, too easy and the higher level kids start to get bored. I try to add something for everyone where possible, but this is also where your games and songs help. If the game is fun and songs are fun, the higher level kids still have a good time with English that is pretty easy for them. Getting kids to teach other can work, but not all young kids have the maturity to do this.