incompetence

"His recent lack of focus in class showed a worrying moral failing. "

"It was evident she was angry, after she slammed the door."

"We need to bring the balance of power into equation"

"The simplest way to solve the math problem was to use the formula directly. "

"It took him only twenty minutes to perform the task."

"During the centuries, the people of Ireland struggled constantly to assert their right to govern themselves."

"The farmer's math of the hay field was impressive—he collected a large amount. "

"He is a student of life."

"My son consistently gets good grades in math class. "

"Her inability to speak French made it difficult to understand the instructions. "

"The teacher praised the student's competence in math. "

"His constant spilling of coffee and tripping over his own feet demonstrated a remarkable level of ineptitude. "