You should try to instill some confidence in your children.
Brad's son Tim comes home sad one day after school because he did poorly on a big math test.
Brad wants Tim to improve his test scores.
Brad tells Tim that he is smart and capable, to keep trying his best and the results will follow.
Brad scolds Tim for his poor grade and threatens to ground him if his scores don't improve.
Tim feels confident and inspired and does very well on his next math test.
Tim feels even worse about his performance and continues to struggle in math class.