Funny, when my younger son finished the 4th grade, his teacher said the same thing to me "I failed" she said, "I failed him, I'm so sorry" (she wasn't talking about his grade)
The fact is, my son was not ready to be a good student. Now he's in a master's program - pure mathematics. But when he was 9, he wanted to run jump and climb trees. He read like a demon, but the rest of the time he was wiggling, throwing things and being annoying.
Get them all on bicycles and take them riding. Then you won't fail. :cool: