Tough Love
In some cases, simply spending more time with the child and assisting them with the lessons will suffice. Some of them would benefit from additional tutoring. Tough love, on the other hand, rarely works on children this age.
Constructive Criticism Please
What more would a child feel if he or she received negative feedback on their work? We recognize that there will always be occasions when poor performance must be addressed, but it is always more beneficial if it is done in a professional manner and criticism is given constructively rather than as a form of insult.