We tried to skip K for DS6 but our school district had a strict age policy for K and 1st grade entrance. We compromised with the principal and had DS6 do half day of K followed by half day of 1st.
Unfortunately this has been a nightmare since both grades are academically woeful for DS6. This has caused behavioral and emotional problems for DS. Ironically, the part of his day that has been most tolerable for DS6 has been K. Perhaps it's the teacher...perhaps it is because it is far less learning to read or academically focused...perhaps everything has been more game focused...perhaps it's because he is allowed to do higher level math work on the computer when he completes assignments...perhaps it's because he is allowed to "help" the other children and supervise actvities...
I honestly wish we hadn't done this hybrid approach since now DS6 has basic given up and views school as a slow, boring place. He always tell me that "maybe he will learn something in X grade" where X grade keeps getting larger and larger.
When in 1st grade DS6 tells me that the other kids don't make a big deal about his age.
